A338732 - OEIS

%I #14 Dec 04 2020 04:20:26

%S 0,0,0,0,1,1,1,1,1,1,1,1,1,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,2,1,3,1,2,2,

%T 2,1,3,1,2,2,2,1,3,1,2,2,2,1,3,1,2,2,3,1,3,1,3,2,2,1,4,1,2,2,3,1,3,1,

%U 3,2,2,1,4,1,2,2,3,1,3,1,4,2,2,1,4,2,2,2,3,1,4,1,3

%N Generating function Sum_{n >= 0} a(n)*x^n = Sum_{k>=1} x^(k*(3*k+1))/(1-x^k).

%C The OEIS contains many very similar sequences, but this one was missing.

%H Seiichi Manyama, <a href="/A338732/b338732.txt">Table of n, a(n) for n = 0..10000</a>

%o (PARI) my(N=66, x='x+O('x^N)); concat([0, 0, 0, 0], Vec(sum(k=1, N, x^(k*(3*k+1))/(1-x^k)))) \\ _Seiichi Manyama_, Dec 04 2020

%Y Cf. A001227, A081757, A117277, A330889, A338730, A338731.

%K nonn

%O 0,15

%A _N. J. A. Sloane_, Dec 03 2020