OFFSET
0,3
COMMENTS
a(30) is negative.
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..400
FORMULA
E.g.f.: exp( Sum_{i>0} Sum_{j>0} sin(x)^(i*j)/(i*j^i) ).
MATHEMATICA
max = 24; Range[0, max]! * CoefficientList[Series[Product[1/(1 - Sin[x]^k/k), {k, 1, max}], {x, 0, max}], x] (* Amiram Eldar, Oct 03 2020 *)
PROG
(PARI) N=40; x='x+O('x^N); Vec(serlaplace(1/prod(k=1, N, 1-sin(x)^k/k)))
(PARI) N=40; x='x+O('x^N); Vec(serlaplace(exp(sum(i=1, N, sum(j=1, N\i, sin(x)^(i*j)/(i*j^i))))))
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Oct 03 2020
STATUS
approved