OFFSET
0,3
MATHEMATICA
nmax = 14; Table[(CoefficientList[Series[Product[Sech[x^k], {k, 1, nmax}], {x, 0, 2 nmax}], x] Range[0, 2 nmax]!)[[n]], {n, 1, 2 nmax + 1, 2}]
CROSSREFS
KEYWORD
sign
AUTHOR
Ilya Gutkovskiy, Dec 17 2019
STATUS
approved