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.

A298641 Number of partitions of n^3 into cubes > 1.

Original entry on oeis.org

1, 0, 1, 1, 2, 1, 8, 6, 45, 100, 377, 1181, 4063, 13225, 45218, 150928, 511970, 1717140, 5777895, 19308880, 64360153, 213446697, 705095144, 2317573307, 7583418322, 24690176885, 80003762726, 257959340058, 827713115396, 2642967441892, 8398644246488
Offset: 0

Views

Author

Ilya Gutkovskiy, Jan 24 2018

Keywords

Examples

			a(4) = 2 because we have [64] and [8, 8, 8, 8, 8, 8, 8, 8].
		

Crossrefs

Programs

  • Maple
    g:= proc(n, L) # number of partitions of n into cubes > 1 and <= L
       option remember;
       local t,k;
       t:= 0;
       if n = 0 then return 1 fi;
       if n < 8 then return 0 fi;
       for k from 2 while k^3 <= min(n,L) do
         t:= t + procname(n-k^3, k^3)
       od
    end proc:
    f:= n -> g(n^3, n^3):
    map(f, [$0..50]); # Robert Israel, Jan 24 2018
  • Mathematica
    mx = 30; s = Series[Product[1/(1 - x^(k^3)), {k, 2, mx}], {x, 0, mx^3}]; Table[ CoefficientList[s, x][[1 + n^3]], {n, 0, mx}] (* Robert G. Wilson v, Jan 24 2018 *)

Formula

a(n) = [x^(n^3)] Product_{k>=2} 1/(1 - x^(k^3)).
a(n) = A078128(A000578(n)).
a(n) ~ exp(4*(Gamma(1/3) * Zeta(4/3))^(3/4) * n^(3/4) / 3^(3/2)) * (Gamma(1/3) * Zeta(4/3))^(3/2) / (8 * 3^(5/2) * Pi^2 * n^6). - Vaclav Kotesovec, Jan 31 2018