OFFSET
0,2
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..1000
FORMULA
G.f.: exp(Sum_{j>=1} ((1 - (-1)^j) / (j*(1 - 1/(4^(j-1)*x^j))) )). - Vaclav Kotesovec, Apr 25 2018
MATHEMATICA
nmax = 30; CoefficientList[Series[Exp[Sum[(1 - (-1)^j) / (j*(1 - 1/(4^(j-1)*x^j))), {j, 1, nmax}]], {x, 0, nmax}], x] (* Vaclav Kotesovec, Apr 25 2018 *)
PROG
(PARI) N=66; x='x+O('x^N); Vec(prod(k=1, N, ((1-4^k*x^k)/(1+4^k*x^k))^(1/4^k)))
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Apr 24 2018
STATUS
approved