OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..230
FORMULA
a(n) ~ (2*n)! * 4 * tan(arcsinh(Pi/2)) / (sqrt(4+Pi^2) * arcsinh(Pi/2)^(2*n+1)). - Vaclav Kotesovec, Jan 24 2015
MATHEMATICA
With[{nn=30}, Take[CoefficientList[Series[Tan[x]*Tan[Sinh[x]], {x, 0, nn}], x]Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Nov 30 2011 *)
PROG
(PARI) x='x+O('x^50); v=Vec(serlaplace(tan(x)*tan(sinh(x)))); concat([0], vector(#v\2, n, v[2*n-1])) \\ G. C. Greubel, Feb 12 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Extended and signs tested by Olivier Gérard, Mar 15 1997
STATUS
approved