OFFSET
0,2
FORMULA
G.f.: theta_4(x/(1 - x)), where theta_4() is the Jacobi theta function.
MATHEMATICA
m = 36; CoefficientList[Series[Product[((1 - x)^k - x^k)/((1 - x)^k + x^k), {k, 1, m}], {x, 0, m}], x] (* Amiram Eldar, May 14 2021 *)
PROG
(PARI) N=66; x='x+O('x^N); Vec(prod(k=1, N, ((1-x)^k-x^k)/((1-x)^k+x^k)))
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Apr 12 2019
STATUS
approved