OFFSET
0,3
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..200
FORMULA
E.g.f.: exp( Sum_{k>0} sigma(k)*tan(x)^k/k ).
MATHEMATICA
nmax = 25; CoefficientList[Series[Product[1/(1 - Tan[x]^k), {k, 1, nmax}], {x, 0, nmax}], x] * Range[0, nmax]! (* Vaclav Kotesovec, Oct 03 2020 *)
PROG
(PARI) N=40; x='x+O('x^N); Vec(serlaplace(1/eta(tan(x))))
(PARI) N=40; x='x+O('x^N); Vec(serlaplace(1/prod(k=1, N, 1-tan(x)^k)))
(PARI) N=40; x='x+O('x^N); Vec(serlaplace(exp(sum(k=1, N, sigma(k)*tan(x)^k/k))))
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Oct 02 2020
STATUS
approved