A319243 Expansion of Product_{k>0} (1 - x^(k^2))/(1 + x^(k^2)).
1, -2, 2, -2, 0, 2, -2, 2, 0, -4, 6, -6, 4, 2, -6, 6, -6, 2, 4, -6, 8, -6, -2, 6, -8, 8, -2, -4, 8, -10, 6, 2, -6, 6, -2, -6, 8, -6, 2, 6, -8, 6, -2, -6, 8, -4, -2, 10, -14, 8, 0, -6, 16, -14, 4, 2, -16, 18, -2, -10, 24, -30, 14, 4, -20, 34, -26, 2, 16, -30, 26, 2, -20
Offset: 0
Keywords
Crossrefs
Programs
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PARI
N=99; x='x+O('x^N); Vec(prod(k=1, sqrtint(N), (1-x^(k^2))/(1+x^(k^2))))
Formula
Convolution inverse of A103265.