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.

A297199 a(n) = number of partitions of n into consecutive positive cubes.

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
Offset: 1

Views

Author

Seiichi Manyama, Jan 15 2018

Keywords

Examples

			    1 = 1^3,                   so   a(1) = 1.
    8 = 2^3,                   so   a(8) = 1.
    9 = 1^3 + 2^3,             so   a(9) = 1.
   27 = 3^3,                   so  a(27) = 1.
   35 = 2^3 + 3^3,             so  a(35) = 1.
   36 = 1^3 + 2^3 + 3^3,       so  a(36) = 1.
   64 = 4^3,                   so  a(64) = 1.
   91 = 3^3 + 4^3,             so  a(91) = 1.
   99 = 2^3 + 3^3 + 4^3,       so  a(99) = 1.
  100 = 1^3 + 2^3 + 3^3 + 4^3, so a(100) = 1.
		

Crossrefs

Programs

  • Maple
    N:= 200: # to get a(1)..a(N)
    F:= (a, b) -> (b^2*(b+1)^2-a^2*(a-1)^2)/4:
    A:= Vector(N):
    for b from 1 to floor(N^(1/3)) do
      for a from b to 1 by -1 do
         v:= F(a,b);
         if v > N then break fi;
         A[v]:= A[v]+1;
    od od:
    convert(A,list); # Robert Israel, Jan 15 2018, corrected Jan 29 2018
  • PARI
    A297199(n) = { my(s=0, k=1, c); while((c=k^3) <= n, my(u=n-c, i=k); while(u>0, i++; c = i^3; u=u-c); s += (!u); k++); (s); }; \\ Antti Karttunen, Aug 22 2019

Formula

a(A217843(n)) >= 1 for n > 1.
a(n) >= 2 for n in A265845. - Robert Israel, Jan 15 2018
G.f.: Sum_{i>=1} Sum_{j>=i} Product_{k=i..j} x^(k^3). - Ilya Gutkovskiy, Apr 18 2019
a(A000578(n)) = A307609(n). - Antti Karttunen, Aug 22 2019