OFFSET
0,4
FORMULA
a(n) ~ n! * cos(Pi*n/2 - sinh(Pi/2)) * 2^(n+2) / Pi^(n+1). - Vaclav Kotesovec, Jul 02 2015
MATHEMATICA
CoefficientList[Series[Exp[Sin[x]]/Cosh[x], {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Jul 02 2015 *)
CROSSREFS
KEYWORD
sign,easy
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
STATUS
approved