login
A009144
Expansion of cosh(sin(x))/cos(x).
0
1, 2, 8, 88, 2176, 78080, 4159616, 307882240, 29920681984, 3710767394816, 571523842998272, 107010484096565248, 23940179383147724800, 6306683724617339961344, 1932337463823712544620544
OFFSET
0,2
FORMULA
a(n) ~ (2*n)! * (exp(1) + exp(-1)) / (Pi/2)^(2*n+1). - Vaclav Kotesovec, Jan 22 2015
MATHEMATICA
Cosh[ Sin[ x ] ]/Cos[ x ] (* Even Part *)
nn = 20; Table[(CoefficientList[Series[Cosh[Sin[x]]*Sec[x], {x, 0, 2*nn}], x] * Range[0, 2*nn]!)[[n]], {n, 1, 2*nn+1, 2}] (* Vaclav Kotesovec, Jan 22 2015 *)
CROSSREFS
Sequence in context: A083831 A134245 A141313 * A132316 A136749 A226321
KEYWORD
nonn
AUTHOR
EXTENSIONS
Extended and signs tested Mar 15 1997 by Olivier Gérard.
STATUS
approved