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Expansion of 1/(Sum_{k>=0} x^(k^3))^2.
1

%I #13 Jun 22 2023 07:20:44

%S 1,-2,3,-4,5,-6,7,-8,7,-4,-1,8,-17,28,-41,56,-70,80,-83,76,-56,20,35,

%T -112,210,-324,445,-562,658,-712,699,-590,357,22,-558,1252,-2084,3008,

%U -3947,4788,-5383,5556,-5116,3864,-1618,-1756,6307,-11956,18454,-25348,31962,-37380

%N Expansion of 1/(Sum_{k>=0} x^(k^3))^2.

%F a(0) = 1; a(n) = -(2/n) * Sum_{k=1..n} A363783(k) * a(n-k).

%o (PARI) my(N=60, x='x+O('x^N)); Vec(1/sum(k=0, N^(1/3), x^k^3)^2)

%Y Convolution inverse of A173677.

%Y Column k=2 of A363779.

%Y Cf. A363783.

%K sign,easy

%O 0,2

%A _Seiichi Manyama_, Jun 21 2023