OFFSET
0,1
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..200
Vaclav Kotesovec, Graph - abs(e.g.f.) in the complex plane
FORMULA
a(n) ~ 2 * (2*n+1)! / ((cosh(r) + 1/(cos(r))^2) * r^(2*n+2)), where r = 0.6897918664614192227814262662202471295055814443118279957952... is the root of the equation sinh(r) + tan(r) = Pi/2. - Vaclav Kotesovec, Feb 07 2015
MATHEMATICA
nn = 20; Table[(CoefficientList[Series[Tan[Sinh[x] + Tan[x]], {x, 0, 2*nn+1}], x] * Range[0, 2*nn+1]!)[[n]], {n, 2, 2*nn, 2}] (* Vaclav Kotesovec, Feb 07 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
STATUS
approved