OFFSET
0,4
FORMULA
G.f.: Product_{k>=1} ((1 - x^(2*k))/(1 - x^(2*k-1)))^k.
MATHEMATICA
nmax = 65; CoefficientList[Series[Product[((1 - x^(2 k))/(1 - x^(2 k - 1)))^k, {k, 1, nmax}], {x, 0, nmax}], x]
CROSSREFS
KEYWORD
sign
AUTHOR
Ilya Gutkovskiy, Dec 03 2017
STATUS
approved