A012639 cos(arcsinh(x)*cos(x))=1-1/2!*x^2+17/4!*x^4-385/6!*x^6+15073/8!*x^8...

1, -1, 17, -385, 15073, -1010945, 101590513, -14396384769, 2765830859457, -694784293696513, 221386930443511505, -87298037019243856513, 41742102489497599699873, -23796035609379191857799425

Offset

0,3

Links

Table of n, a(n) for n=0..13.

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

Sequence in context: A132541 A159244 A318043 * A350926 A327732 A012200

Adjacent sequences: A012636 A012637 A012638 * A012640 A012641 A012642

Keyword

sign

Author

Patrick Demichel (patrick.demichel(AT)hp.com)

Status

approved