OFFSET
0,3
LINKS
Robert Israel, Table of n, a(n) for n = 0..384
FORMULA
a(n) ~ sqrt(1+exp(-2)) * arctan(exp(-1))^(1/2-n) * exp(1/2-n) * n^(n-1).
MAPLE
S:= series(-LambertW(-tan(x)), x, 31):
seq(coeff(S, x, n)*n!, n=0..30); # Robert Israel, Mar 09 2017
MATHEMATICA
CoefficientList[Series[-LambertW[-Tan[x]], {x, 0, 20}], x] * Range[0, 20]!
PROG
(PARI) x='x+O('x^50); concat([0], Vec(serlaplace(-lambertw(-tan(x))))) \\ G. C. Greubel, Nov 07 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Oct 18 2016
STATUS
approved