OFFSET
0,3
FORMULA
a(n) ~ (-1)^n * sinh(Pi*cosh(1)/2) * cosh(1) * 2^(2*n) * n^(2*n-1) / exp(2*n). - Vaclav Kotesovec, Nov 01 2013
MATHEMATICA
Table[n!*SeriesCoefficient[Cos[ArcSinh[x]*Cos[x]], {x, 0, n}], {n, 0, 40, 2}] (* Vaclav Kotesovec, Nov 01 2013 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
STATUS
approved