OFFSET
0,3
FORMULA
a(n) ~ (-1)^(n+1) * sin(sinh(Pi/2)) * cosh(Pi/2) * 2^(2*n) * n^(2*n-1) / exp(2*n). - Vaclav Kotesovec, Oct 30 2013
MATHEMATICA
Table[n!*SeriesCoefficient[Cosh[Sin[ArcSinh[x]]], {x, 0, n}], {n, 0, 40, 2}] (* Vaclav Kotesovec, Oct 30 2013 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
STATUS
approved