OFFSET
0,3
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..385
FORMULA
a(n) ~ tan(exp(-1)) * n^n.
MATHEMATICA
CoefficientList[Series[Tan[x]/(1+LambertW[-x]), {x, 0, 25}], x] * Range[0, 25]!
Table[Sin[Pi*n/2] * 2^(n+1) * (2^(n+1) - 1) * BernoulliB[n+1] / (n+1) + Sum[Binomial[n, k] * Sin[Pi*k/2] * 2^(k+1) * (2^(k+1)-1) * BernoulliB[k+1] /(k+1) * (n-k)^(n-k), {k, 0, n-1}], {n, 0, 25}] (* Vaclav Kotesovec, Oct 28 2016 *)
PROG
(PARI) x='x+O('x^30); concat([0], Vec(serlaplace(tan(x)/(1 + lambertw(-x))))) \\ G. C. Greubel, May 29 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Oct 16 2016
STATUS
approved