800 (number)

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800 (eight hundred) is the natural number following 799 and preceding 801.

It is the sum of four consecutive primes (193 + 197 + 199 + 211). It is a Harshad number, an Achilles number and the area of a square with diagonal 40.[1]

Integers from 801 to 899

800s

801

801 is a Harshad number. 801 is the sum of a square and positive cube in more than one way, and a sum of distinct positive cubes in more than one way:[2][3]

801=172+83=262+53=13+23+43+63+83=23+43+93.{\displaystyle 801=17^{2}+8^{3}=26^{2}+5^{3}=1^{3}+2^{3}+4^{3}+6^{3}+8^{3}=2^{3}+4^{3}+9^{3}.}

In the gematria of 2nd century bishop Irenaeus, 801 stands for both the Greek word for a dove, and for Alpha and Omega, and therefore represents God in two ways.[4]

There are 801 club patterns in a 50x50 grid of coins.[5]

802

802 = 2 × 401. It is a nontotient, a happy number, the sum of eight consecutive primes (83 + 89 + 97 + 101 + 103 + 107 + 109 + 113), and the sum of 4 consecutive triangular numbers[6] (171 + 190 + 210 + 231).

803

803 = 11 × 73. It is a Harshad number, the sum of three consecutive primes (263 + 269 + 271), and the sum of nine consecutive primes (71 + 73 + 79 + 83 + 89 + 97 + 101 + 103 + 107).

There are 803 partitions of 34 into Fibonacci parts.[7]

804

804 = 22 × 3 × 67. It is a nontotient, a Harshad number, and a refactorable number.[8]

"The 804" is a local nickname for the Greater Richmond Region of the U.S. state of Virginia, derived from its telephone area code (although the area code covers a larger area).[9][10]

805

805 = 5 × 7 × 23. It is a sphenic number. There are 805 partitions of 38 into nonprime parts[11]

806

806 = 2 × 13 × 31. It is a sphenic number, a nontotient, a happy number, and the totient sum for first 51 integers.

806 = Phi(51)[12]

807

807 = 3 × 269 = antisigma(42)[13]

808

808 = 23 × 101. It is a refactorable number and a strobogrammatic number.[14]

809

809 is a prime number, a Sophie Germain prime,[15] a Chen prime, and an Eisenstein prime with no imaginary part.

810s

810

810 = 2 × 34 × 5. It is a harshad number. There are 810 non-equivalent ways of expressing 100,000 as the sum of two prime numbers.[16] Theree are 810 distinct reduced words of length 5 in the Coxeter group of "Apollonian reflections" in three dimensions.[17]

811

811 is a prime number, a twin prime, a Chen prime, the largest minimal prime in base 9, and the sum of five consecutive primes (151 + 157 + 163 + 167 + 173). It is a happy number and a zero of Mertens function.

812

812 = 22 × 7 × 29. It is an admirable number, a pronic number,[18] a balanced number,[19] and a zero of Mertens function.

813

813 = 3 × 271. It is a Blum integer.[20]

814

814 = 2 × 11 × 37. It is a sphenic number, a nontotient, and a zero of Mertens function. There are 814 fixed hexahexes.

815

815 = 5 × 163. There are 815 graphs with 8 vertices and a distinguished bipartite block.[21]

816

816 = 24 × 3 × 17. It is a tetrahedral number,[22] a Padovan number,[23] and a Zuckerman number.

817

817 = 19 × 43. It is a centered hexagonal number[24] and the sum of three consecutive primes (269 + 271 + 277).

818

818 = 2 × 409. It is a nontotient and a strobogrammatic number[14]

819

819 = 32 × 7 × 13. It is a square pyramidal number.[25]

820s

820

820 = 22 × 5 × 41. It is a Harshad number, a happy number, a repdigit (1111) in base 9, and the 40th triangular number.[26]

821

821 is a prime number, a twin prime, a Chen prime, and an Eisenstein prime with no imaginary part. It forms a prime quadruplet with 823, 827, and 829. It is a lazy caterer number.[27]

822

822 = 2 × 3 × 137. It is a sphenic number, a member of the Mian–Chowla sequence,[28] and the sum of twelve consecutive primes (43 + 47 + 53 + 59 + 61 + 67 + 71 + 73 + 79 + 83 + 89 + 97).

823

823 is a prime number, a twin prime, and a lucky prime. It forms a prime quadruplet with 821, 827, and 829. It is a zero of Mertens function.

824

824 = 23 × 103, refactorable number, nontotient, a zero of Mertens function, and the sum of ten consecutive primes (61 + 67 + 71 + 73 + 79 + 83 + 89 + 97 + 101 + 103).

825

825 = 3 × 52 × 11. It is a Smith number,[29] a Harshad number, and a zero of Mertens function.

826

826 = 2 × 7 × 59. It is a sphenic number. There are 825 partitions of 29 into parts each of which is used a different number of times.[30]

827

827 is a prime number, a twin prime, a Chen prime, a Eisenstein prime with no imaginary part, and the sum of seven consecutive primes (103 + 107 + 109 + 113 + 127 + 131 + 137). It forms a prime quadruplet with 821, 823, and 829. It is a strictly non-palindromic number.[31]

828

828 = 22 × 32 × 23. It is a Harshad number and a triangular matchstick number.[32]

829

829 is a prime number, a twin prime, a Chen prime, and the sum of three consecutive primes (271 + 277 + 281). It forms a prime quadruplet with 821, 823, and 827. It is a centered triangular number.

830s

830

830 = 2 × 5 × 83. It is a sphenic number, a nontotient, the totient sum of the first 52 integers, and the sum of four consecutive primes (197 + 199 + 211 + 223).

831

831 = 3 × 277. There are 831 partitions of 32 into at most 5 parts.[33]

832

832 = 26 × 13. It is a Harshad number and a member of the Horadam sequence (0,1,4,2).[34]

833

833 = 72 × 17. It is an octagonal number[35] and a centered octahedral number.[36]

834

834 = 2 × 3 × 139. It is a cake number, a sphenic number, a nontotient, and the sum of six consecutive primes (127 + 131 + 137 + 139 + 149 + 151).

835

835 = 5 × 167. It is a Motzkin number.[37]

836

The factorization of 836 is 22 × 11 × 19, so its proper factors are 1, 2, 4, 11, 19, 22, 38, 44, 76, 209, and 418. They sum to 844. As this is greater than 836, it is an abundant number, but no subset sums to 836, so it is not a semiperfect number; therefore it is a weird number.[38] Besides, 836 is the smallest weird number that is also an untouchable number, i.e. there is no n such that the sum of proper factors of n equals 836. (The only smaller weird number, 70, is not untouchable, since σ(134) − 134 = 70).

837

837 = 33 × 31. It is the 36th generalized heptagonal number.[39]

838

838 = 2 × 419. It is a palindromic number. There are 838 distinct products ijk with 1 <= i<j<k <= 23.[40]

839

839 is a prime number, a safe prime,[41] a Chen prime, an Eisenstein prime with no imaginary part, and the sum of five consecutive primes (157 + 163 + 167 + 173 + 179). It is a highly cototient number.[42]

840s

840

841

841 = 292 = 202 + 212, sum of three consecutive primes (277 + 281 + 283), sum of nine consecutive primes (73 + 79 + 83 + 89 + 97 + 101 + 103 + 107 + 109), centered square number,[43]centered heptagonal number,[44]centered octagonal number[45]

842

842 = 2 × 421. It is a nontotient. There are 842 series-reduced trees with 18 nodes.[46]

842!! - 1 is prime.[47]

843

843 = 3 × 281. It is a Lucas number.[48]

844

844 = 22 × 211. It is a nontotient. It is the smallest 5 consecutive integers which are not squarefree:

844 = 22 × 211, 845 = 5 × 132, 846 = 2 × 32 × 47, 847 = 7 × 112, and 848 = 24 × 53.[49]

845

845 = 5 × 132. It is a concentric pentagonal number.[50]There are 845 emergent parts in all partitions of 22.[51]

846

846 = 2 × 32 × 47. It is a nontotient, a Harshad number, and the sum of eight consecutive primes (89 + 97 + 101 + 103 + 107 + 109 + 113 + 127).

847

847 = 7 × 112. It is a happy number. There are 847 partitions of 29 that do not contain 1 as a part.[52]

848

848 = 24 × 53. It is an untouchable number.

849

849 = 3 × 283, It is a zero of Mertens function and a Blum integer.

850s

850

850 = 2 × 52 × 17. It is a zero of Mertens function and a nontotient. The sum of the squares of the divisors of 26 is 850 (sequence A001157 in the OEIS).

The maximum possible Fair Isaac credit score is 850.

851

851 = 23 × 37 There are 851 compositions of 18 into distinct parts[53]

852

852 = 22 × 3 × 71. It is a pentagonal number[54] and a Smith number.[29]

853

853 is a prime number, a Perrin number,[55] a zero of Mertens function, and a strictly non-palindromic number. The average of first 853 prime numbers is an integer (sequence A045345 in the OEIS). There are 853 connected graphs with 7 nodes.

854

854 = 2 × 7 × 61. It is a sphenic number and a nontotient. There are 854 unlabeled planar trees with 11 nodes.[56]

855

855 = 32 × 5 × 19. It is a decagonal number[57] and a centered cube number.[58]

856

856 = 23 × 107. It is a nonagonal number,[59] a centered pentagonal number,[60] and a refactorable number.

857

857 is a prime number, a Chen prime, an Eisenstein prime with no imaginary part, and the sum of three consecutive primes (281 + 283 + 293).

858

858 = 2 × 3 × 11 × 13. It is a Giuga number.[61]

859

859 is a prime number and a prime index prime. There are 859 planar partitions of 11.[62]

860s

860

860 = 22 × 5 × 43. It is aHoax number[63] and the sum of four consecutive primes (199 + 211 + 223 + 227).

861

861 = 3 × 7 × 41. It is a sphenic number, a hexagonal number,[64] a Smith number,[29] and the 41st triangular number.[26]

862

862 = 2 × 431. It is a lazy caterer number.[65]

863

863 is a prime number, a safe prime,[41] a Chen prime, an Eisenstein prime with no imaginary part, and an index of a prime Lucas number.[66]It is the sum of five consecutive primes (163 + 167 + 173 + 179 + 181) and the sum of seven consecutive primes (107 + 109 + 113 + 127 + 131 + 137 + 139).

864

864 = 25 × 33. It is an Achilles number and a Harshad number. It the sum of a twin prime pair (431 + 433) and the sum of six consecutive primes (131 + 137 + 139 + 149 + 151 + 157).

865

865 = 5 × 173.

866

866 = 2 × 433. It is a nontotient and the number of cubes of edge length 1 required to make a hollow cube of edge length 13. There are 866 one-sided noniamonds.[67]

867

867 = 3 × 172. There are 867 5-chromatic simple graphs on 8 nodes.[68]

868

868 = 22 × 7 × 31 = J3(10).[69] It is a nontotient.

869

869 = 11 × 79. It is a zero of Mertens function.

870s

870

870 = 2 × 3 × 5 × 29. It is a pronic number,[18] a nontotient, a sparsely totient number,[70] a Harshad number, and the sum of ten consecutive primes (67 + 71 + 73 + 79 + 83 + 89 + 97 + 101 + 103 + 107). It is the magic constant of n×n normal magic square and n-queens problem for n = 12.

871

871 = 13 × 67. It is the thirteenth tridecagonal number.

872

872 = 23 × 109. It is a refactorable number and anontotient.

872! + 1 is prime.

873

873 = 32 × 97 = 1! + 2! + 3! + 4! + 5! + 6!.

874

874 = 2 × 19 × 23 = 0! + 1! + 2! + 3! + 4! + 5! + 6!. It is a sphenic number, a nontotient, a Harshad number, a happy number, and the sum of the first twenty-three primes.

875

875 = 53 × 7. It can be uniquely expressed as a difference of two positive cubes: 875 = 103 – 53.[71]

876

876 = 22 × 3 × 73. It is a generalized pentagonal number.[72]

877

877 is a prime number, a prime index prime, a Chen prime, a zero of Mertens function, a Bell number,[73] and a strictly non-palindromic number.[31]

878

878 = 2 × 439. It is a nontotient. There are 878 Pythagorean triples with a hypotenuse less than 1000.[74]

879

879 = 3 × 293. It is a candidate Lychrel seed number. There are 879 regular hypergraphs spanning 4 vertices.[75]

880s

880

880 = 24 × 5 × 11 = 11!!!.[76] It is a Harshad number and a 148-gonal number. There are 880 n×nmagic squares for n = 4.[77]

881

881 is a prime number, a twin prime, a Chen prime, an Eisenstein prime with no imaginary part, and the sum of nine consecutive primes (79 + 83 + 89 + 97 + 101 + 103 + 107 + 109 + 113). It is a happy number.

881 is a bilingual play on words when text chatting in Mandarin Chinese or bilingually Mandarin Chinese and English. "881" is pronounced ba ba yi in Mandarin, and thus puns on "bye-bye." Probably an elaboration of the similar pun on "88" (ba-ba). See 88 (number).

882

882 = 2 × 32 × 72 = (95)2{\displaystyle {\binom {9}{5}}_{2}} It is a trinomial coefficient,[78] a Harshad number, and the totient sum of the first 53 integers.

883

883 is a prime number, a twin prime, a lucky prime, the sum of three consecutive primes (283 + 293 + 307), and the sum of eleven consecutive primes (59 + 61 + 67 + 71 + 73 + 79 + 83 + 89 + 97 + 101 + 103). It is a zero of Mertens function.

884

884 = 22 × 13 × 17. It is a zero of Mertens function. There are 884 points on surface of tetrahedron with sidelength 21.[79]

885

885 = 3 × 5 × 59. It is a sphenic number. There are 885 series-reduced rooted trees whose leaves are integer partitions whose multiset union is an integer partition of 7.[80]

886

886 = 2 × 443. It is a zero of Mertens function.

887

887 is a prime number followed by primal gap of 20, a safe prime,[41] a Chen prime, and an Eisenstein prime with no imaginary part. It is the first iteration of the 196 trajectory (196 + 691 = 887).

888

889

889 = 7 × 127. It is a zero of Mertens function.

890s

890

890 = 2 × 5 × 89. It is a sphenic number, a nontotient, and the sum of four consecutive primes (211 + 223 + 227 + 229). 890 is the sum of the squares of two successive primes: 890 = 192 + 232.[81]

891

891 = 34 × 11. It is an octahedral number and the sum of five consecutive primes (167 + 173 + 179 + 181 + 191).

892

892 = 22 × 223. It is a nontotient. There are 892 regions formed by drawing the line segments connecting any two perimeter points of a 6 times 2 grid of squares like this(sequence A331452 in the OEIS).

893

893 = 19 × 47. It is a zero of Mertens function.

893 is considered an unlucky number in Japan, because its digits read sequentially are the literal translation of yakuza.

894

894 = 2 × 3 × 149. It is a sphenic number and a nontotient.

895

895 = 5 × 179. It is a Smith number,[29] a Woodall number,[82] and a zero of Mertens function.

896

896 = 27 × 7. It is a refactorable number, a zero of Mertens function, and the sum of six consecutive primes (137 + 139 + 149 + 151 + 157 + 163).

897

897 = 3 × 13 × 23. It is a sphenic number and a Cullen number (sequence A002064 in the OEIS).

898

898 = 2 × 449. It is a nontotient and a zero of Mertens function.

899

899 = 29 × 31. It is the product of a pair of twin primes,[83] a happy number, and the smallest number with digit sum 26.[84] There are 899 partitions of 51 into prime parts.

References

  1. ↑Sloane, N. J. A. (ed.). "SequenceA001105(a(n) = 2*n^2)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  2. ↑Sloane, N. J. A. (ed.). "SequenceA003998(Numbers that are a sum of distinct positive cubes in more than one way)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  3. ↑Sloane, N. J. A. (ed.). "SequenceA055393(Sum of a square and a nonnegative cube in more than one way)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  4. ↑Barry, Kieren (1999), The Greek Qabalah: Alphabetical Mysticism and Numerology in the Ancient World, Weiser Books, pp. 110–111, ISBN 9781609252274.
  5. ↑"A229093 - OEIS". oeis.org. Retrieved 2026-06-15.
  6. ↑(sequence A005893 in the OEIS)
  7. ↑Sloane, N. J. A. (ed.). "SequenceA003107(Number of partitions of n into Fibonacci parts (with a single type of 1))". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-25.
  8. ↑Sloane, N. J. A. (ed.). "SequenceA174457(Infinitely refactorable numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2023-10-16.
  9. ↑"Richmond is getting a new area code. Not everyone is thrilled: 'I'll be 804 forever'". WTVR-TV. Retrieved 2025-03-16.
  10. ↑Karri Peifer. "The 804 is running out of numbers". AXIOS Richmond. Retrieved 2025-03-16.
  11. ↑Sloane, N. J. A. (ed.). "SequenceA002095(Number of partitions of n into nonprime parts)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-25.
  12. ↑Sloane, N. J. A. (ed.). "SequenceA002088(Sum of totient function: a(n) = Sum_{k=1..n} phi(k), cf. A000010)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-25.
  13. ↑Sloane, N. J. A. (ed.). "SequenceA024816(Antisigma(n): Sum of the numbers less than n that do not divide n)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-25.
  14. 12Sloane, N. J. A. (ed.). "SequenceA000787(Strobogrammatic numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  15. ↑Sloane, N. J. A. (ed.). "SequenceA005384(Sophie Germain primes)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  16. ↑Sloane, N. J. A. (ed.). "SequenceA065577(Number of Goldbach partitions of 10^n)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2023-08-31.
  17. ↑Sloane, N. J. A. (ed.). "SequenceA154638(a(n) is the number of distinct reduced words of length n in the Coxeter group of "Apollonian reflections" in three dimensions)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-25.
  18. 12Sloane, N. J. A. (ed.). "SequenceA002378(Oblong (or promic, pronic, or heteromecic) numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  19. ↑Sloane, N. J. A. (ed.). "SequenceA020492(Balanced numbers: numbers k such that phi(k) (A000010) divides sigma(k) (A000203))". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  20. ↑"A016105 - OEIS". oeis.org. Retrieved 2026-07-06.
  21. ↑Sloane, N. J. A. (ed.). "SequenceA049312(Number of graphs with a distinguished bipartite block, by number of vertices)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-25.
  22. ↑Sloane, N. J. A. (ed.). "SequenceA000292(Tetrahedral numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  23. ↑Sloane, N. J. A. (ed.). "SequenceA000931(Padovan sequence)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  24. ↑Sloane, N. J. A. (ed.). "SequenceA003215(Hex (or centered hexagonal) numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  25. ↑Sloane, N. J. A. (ed.). "SequenceA000330(Square pyramidal numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  26. 12Sloane, N. J. A. (ed.). "SequenceA000217(Triangular numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  27. ↑"A000124 - OEIS". oeis.org. Retrieved 2026-07-06.
  28. ↑Sloane, N. J. A. (ed.). "SequenceA005282(Mian-Chowla sequence)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  29. 1234Sloane, N. J. A. (ed.). "SequenceA006753(Smith numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  30. ↑Sloane, N. J. A. (ed.). "SequenceA098859(Number of partitions of n into parts each of which is used a different number of times)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-25.
  31. 12Sloane, N. J. A. (ed.). "SequenceA016038(Strictly non-palindromic numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  32. ↑(sequence A045943 in the OEIS)
  33. ↑Sloane, N. J. A. (ed.). "SequenceA001401(Number of partitions of n into at most 5 parts)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-25.
  34. ↑(sequence A085449 in the OEIS)
  35. ↑"A000567 - OEIS". oeis.org. Retrieved 2026-07-06.
  36. ↑Sloane, N. J. A. (ed.). "SequenceA001845(Centered octahedral numbers (crystal ball sequence for cubic lattice))". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-06-02.
  37. ↑Sloane, N. J. A. (ed.). "SequenceA001006(Motzkin numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  38. ↑"Sloane's A006037 : Weird numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-02.
  39. ↑Sloane, N. J. A. (ed.). "SequenceA085787(Generalized heptagonal numbers: m*(5*m – 3)/2, m = 0, +-1, +-2 +-3, ...)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-30.
  40. ↑Sloane, N. J. A. (ed.). "SequenceA027430(Number of distinct products ijk with 1 <= i<j<k <= n)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  41. 123Sloane, N. J. A. (ed.). "SequenceA005385(Safe primes)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  42. ↑Sloane, N. J. A. (ed.). "SequenceA100827(Highly cototient numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  43. ↑Sloane, N. J. A. (ed.). "SequenceA001844(Centered square numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  44. ↑Sloane, N. J. A. (ed.). "SequenceA069099(Centered heptagonal numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  45. ↑Sloane, N. J. A. (ed.). "SequenceA016754(Odd squares: a(n) = (2n+1)^2. Also centered octagonal numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  46. ↑Sloane, N. J. A. (ed.). "SequenceA000014(Number of series-reduced trees with n nodes)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  47. ↑Sloane, N. J. A. (ed.). "SequenceA007749(Numbers k such that k!! - 1 is prime)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-24.
  48. ↑Sloane, N. J. A. (ed.). "SequenceA000032(Lucas numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  49. ↑Sloane, N. J. A. (ed.). "SequenceA045882(Smallest term of first run of (at least) n consecutive integers which are not squarefree)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-24.
  50. ↑Sloane, N. J. A. (ed.). "SequenceA032527(Concentric pentagonal numbers: floor( 5*n^2 / 4 ))". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-24.
  51. ↑Sloane, N. J. A. (ed.). "SequenceA182699(Number of emergent parts in all partitions of n)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-24.
  52. ↑Sloane, N. J. A. (ed.). "SequenceA002865(Number of partitions of n that do not contain 1 as a part)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-24.
  53. ↑Sloane, N. J. A. (ed.). "SequenceA032020(Number of compositions (ordered partitions) of n into distinct parts)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-24.
  54. ↑Sloane, N. J. A. (ed.). "SequenceA000326(Pentagonal numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  55. ↑Sloane, N. J. A. (ed.). "SequenceA001608(Perrin sequence)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  56. ↑Sloane, N. J. A. (ed.). "SequenceA002995(Number of unlabeled planar trees (also called plane trees) with n nodes)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-24.
  57. ↑Sloane, N. J. A. (ed.). "SequenceA001107(10-gonal (or decagonal) numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  58. ↑Sloane, N. J. A. (ed.). "SequenceA005898(Centered cube numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  59. ↑Sloane, N. J. A. (ed.). "SequenceA001106(9-gonal (or enneagonal or nonagonal) numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  60. ↑Sloane, N. J. A. (ed.). "SequenceA005891(Centered pentagonal numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  61. ↑Sloane, N. J. A. (ed.). "SequenceA007850(Giuga numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  62. ↑Sloane, N. J. A. (ed.). "SequenceA000219(Number of planar partitions (or plane partitions) of n)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-24.
  63. ↑Sloane, N. J. A. (ed.). "SequenceA019506(Hoax numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-24.
  64. ↑Sloane, N. J. A. (ed.). "SequenceA000384(Hexagonal numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  65. ↑"A000124 - OEIS". oeis.org. Retrieved 2026-07-09.
  66. ↑Sloane, N. J. A. (ed.). "SequenceA001606(Indices of prime Lucas numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
  67. ↑Sloane, N. J. A. (ed.). "SequenceA006534". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-10.
  68. ↑Sloane, N. J. A. (ed.). "SequenceA076281(Number of 5-chromatic (i.e., chromatic number equals 5) simple graphs on n nodes)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-24.
  69. ↑Sloane, N. J. A. (ed.). "SequenceA059376(Jordan function J_3(n))". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-24.
  70. ↑Sloane, N. J. A. (ed.). "SequenceA036913(Sparsely totient numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  71. ↑Sloane, N. J. A. (ed.). "SequenceA014439(Differences between two positive cubes in exactly 1 way.)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2019-08-18.
  72. ↑Sloane, N. J. A. (ed.). "SequenceA001318(Generalized pentagonal numbers.)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2019-08-26.
  73. ↑Sloane, N. J. A. (ed.). "SequenceA000110(Bell or exponential numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  74. ↑Sloane, N. J. A. (ed.). "SequenceA101929(Number of Pythagorean triples with hypotenuse < 10^n.)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-11.
  75. ↑Sloane, N. J. A. (ed.). "SequenceA319190(Number of regular hypergraphs)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2019-08-18.
  76. ↑Sloane, N. J. A. (ed.). "SequenceA007661(Triple factorial numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-11.
  77. ↑"Sloane's A006052 : Number of magic squares of order n composed of the numbers from 1 to n^2, counted up to rotations and reflections". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-02.
  78. ↑Sloane, N. J. A. (ed.). "SequenceA111808(Left half of trinomial triangle (A027907), triangle read by rows)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-11.
  79. ↑Sloane, N. J. A. (ed.). "SequenceA005893(Number of points on surface of tetrahedron)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-11.
  80. ↑Sloane, N. J. A. (ed.). "SequenceA319312(Number of series-reduced rooted trees whose leaves are integer partitions whose multiset union is an integer partition of n)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-11.
  81. ↑Sloane, N. J. A. (ed.). "SequenceA069484(a(n) = prime(n+1)^2 + prime(n)^2.)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-11.
  82. ↑Sloane, N. J. A. (ed.). "SequenceA003261(Woodall numbers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-06-11.
  83. ↑Sloane, N. J. A. (ed.). "SequenceA037074(Numbers that are the product of a pair of twin primes)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-11.
  84. ↑Sloane, N. J. A. (ed.). "SequenceA051885(Smallest number whose sum of digits is n)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2022-05-11.