A319244 Expansion of Product_{k>0} (1 - x^(k^3))/(1 + x^(k^3)).

1, -2, 2, -2, 2, -2, 2, -2, 0, 2, -2, 2, -2, 2, -2, 2, 0, -2, 2, -2, 2, -2, 2, -2, 0, 2, -2, 0, 2, -2, 2, -2, 4, -6, 6, -2, -2, 2, -2, 2, -4, 6, -6, 2, 2, -2, 2, -2, 4, -6, 6, -2, -2, 2, 0, -2, 0, 2, -2, -2, 6, -6, 2, 2, -2, 2, -2, 6, -10, 10, -6, 2, 0, -2, 2, -6, 10

Offset: 0

Author

Seiichi Manyama, Sep 15 2018

Keywords

• sign

Crossrefs

Product_{k>0} (1 - x^(k^m))/(1 + x^(k^m)): A002448 (m=1), A319243 (m=2), this sequence (m=3).

Cf. A280263.

Programs

Mathematica

CoefficientList[Series[Product[(1-x^(k^3))/(1+x^(k^3)),{k,10}],{x,0,80}],x] (* Harvey P. Dale, Nov 10 2024 *)

Formula

Convolution inverse of A280263.