OFFSET
0,2
FORMULA
a(n) ~ (2*n)! * 4 / (sqrt(4+Pi^2) * log((Pi + sqrt(4+Pi^2))/2)^(2*n)). - Vaclav Kotesovec, Jan 23 2015
MATHEMATICA
Tan[ Sinh[ x ] ]*x (* Even Part *)
nn = 20; Table[(CoefficientList[Series[x*Tan[Sinh[x]], {x, 0, 2*nn}], x] * Range[0, 2*nn]!)[[n]], {n, 1, 2*nn+1, 2}] (* Vaclav Kotesovec, Jan 23 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Extended and signs tested Mar 15 1997 by Olivier Gérard.
STATUS
approved