cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-2 of 2 results.

A025453 Number of partitions of n into 9 nonnegative cubes.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 1, 2, 2, 2, 3, 2, 2, 1, 1, 2, 2, 2, 2, 2, 1, 1, 1, 2, 2, 1, 2, 1, 1, 2, 2, 3, 2, 2, 2, 2, 2, 2, 2, 3, 3, 2, 3, 3, 2, 3, 2, 4, 2, 2, 3, 2, 2, 2, 2, 2, 3, 3, 3, 3, 2, 3, 2, 2, 3, 2, 4, 3, 3, 3, 2, 3, 3, 3, 3, 3, 2, 2, 2, 2, 3, 2, 3
Offset: 0

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Author

Keywords

Examples

			a(8) = 2 via 8*0^3 + 1*2^3 = 1 * 0^3 + 8*1^3.
		

Crossrefs

Programs

  • Maple
    f:= proc(x,m,M)
    local i;
    option remember;
      if x = 0 then return 1
      elif m = 0 then return 0
      fi;
      add(procname(x-i^3, m-1, i), i=1..min(M,floor(x^(1/3))));
    end proc:
    map(f, [$0..150],9,150); # Robert Israel, Jan 23 2025
  • PARI
    first(n) = my(v=vector(n), maxb=sqrtnint(n, 3)); forvec(x=vector(9, i, [0, maxb]), s=sum(i=1, 9, x[i]^3); if(0David A. Corneth, Jan 23 2025

A307738 Number of partitions of n^3 into at most n cubes.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 3, 4, 7, 18, 36, 66, 157, 329, 728, 1611, 3655, 8062, 18154, 40358, 89807, 199778, 444419, 984422, 2183461, 4827756, 10651083, 23465459, 51576034, 113092423, 247546849, 540538832, 1177836149, 2560897979, 5555722749, 12025952101, 25976048200
Offset: 0

Author

Ilya Gutkovskiy, Apr 25 2019

Keywords

Comments

Does a(n+1) / a(n) ~ 2? - David A. Corneth, Sep 27 2019

Examples

			7^3 =
1^3 + 1^3 + 5^3 + 6^3 =
1^3 + 1^3 + 3^3 + 4^3 + 5^3 + 5^3 =
1^3 + 2^3 + 3^3 + 3^3 + 4^3 + 6^3,
so a(7) = 4.
		

Programs

  • PARI
    a(n) = {my(res = 0); res=aIterate(n^3, 1, n); res }
    aIterate(s, m, q) = { if(s == 0, return(1)); if(q == 0, return(0)); sum(i = m, sqrtnint(s, 3), aIterate(s - i^3, i, q-1) ) } \\ David A. Corneth, Sep 23 2019

Extensions

a(21)-a(36) from David A. Corneth, Sep 23 2019
Showing 1-2 of 2 results.