A012349 cosh(arcsin(x)*arcsin(x))=1+12/4!*x^4+240/6!*x^6+11088/8!*x^8...

1, 0, 12, 240, 11088, 831360, 92908992, 14524194048, 3032137705728, 815977299898368, 275301139727035392, 113869459498923110400, 56685373204085048463360, 33442869828080671395840000

Offset

0,3

Links

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

Formula

a(n) ~ sqrt(Pi) * sinh(Pi^2/4) * (2*n)! / (2 * n^(3/2)). - Vaclav Kotesovec, Feb 08 2015

Mathematica

nn = 20; Table[(CoefficientList[Series[Cosh[ArcSin[x]^2], {x, 0, 2*nn}], x] * Range[0, 2*nn]!)[[n]], {n, 1, 2*nn+1, 2}] (* Vaclav Kotesovec, Feb 08 2015 *)

Crossrefs

Sequence in context: A012542 A009166 A174556 * A012302 A012543 A012350

Adjacent sequences: A012346 A012347 A012348 * A012350 A012351 A012352

Keyword

nonn

Author

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

Status

approved