A012341 arcsin(arcsin(x)*arcsin(x))=2/2!*x^2+8/4!*x^4+248/6!*x^6+11328/8!*x^8...

0, 2, 8, 248, 11328, 1091232, 148080000, 30317577600, 8228536780800, 2957031184028160, 1336782441018009600, 749500660718368634880, 508063303148296391147520, 410659058984740631962951680

Offset

0,2

Links

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

Formula

a(n) ~ sqrt(tan(1)) * (2*n)! / (sqrt(2*Pi) * n^(3/2) * (sin(1))^(2*n)). - Vaclav Kotesovec, Feb 08 2015

Mathematica

nn = 20; Table[(CoefficientList[Series[ArcSin[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: A067583 A120378 A012345 * A299374 A203317 A258161

Adjacent sequences: A012338 A012339 A012340 * A012342 A012343 A012344

Keyword

nonn

Author

Patrick Demichel

Extensions

a(0)=0 prepended by Vaclav Kotesovec, Feb 08 2015

Status

approved