OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..385
FORMULA
a(n) ~ n^(n-1) / (4*(1+exp(-1))).
MATHEMATICA
CoefficientList[Series[-1/(1-LambertW[-x])/(1+x), {x, 0, 20}], x] * Range[0, 20]!
PROG
(PARI) x='x+O('x^50); Vec(serlaplace(-1/((1 - lambertw(-x))*(1+x)))) \\ G. C. Greubel, Nov 08 2017
CROSSREFS
KEYWORD
sign
AUTHOR
Vaclav Kotesovec, Oct 18 2016
STATUS
approved