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Expansion of 1/Sum_{k>=0} x^(k^5).
3

%I #15 Jun 20 2023 07:43:51

%S 1,-1,1,-1,1,-1,1,-1,1,-1,1,-1,1,-1,1,-1,1,-1,1,-1,1,-1,1,-1,1,-1,1,

%T -1,1,-1,1,-1,0,1,-2,3,-4,5,-6,7,-8,9,-10,11,-12,13,-14,15,-16,17,-18,

%U 19,-20,21,-22,23,-24,25,-26,27,-28,29,-30,31,-31,30,-28,25,-21,16,-10,3,5,-14,24,-35,47,-60,74,-89,105,-122

%N Expansion of 1/Sum_{k>=0} x^(k^5).

%H Seiichi Manyama, <a href="/A352530/b352530.txt">Table of n, a(n) for n = 0..10000</a>

%o (PARI) my(N=99, x='x+O('x^N)); Vec(1/sum(k=0, N^(1/5), x^k^5))

%o (PARI) a(n) = if(n==0, 1, -sum(k=1, n, ispower(k, 5)*a(n-k)));

%Y Cf. A000584, A317665, A323633, A352529.

%K sign

%O 0,35

%A _Seiichi Manyama_, Mar 19 2022