A012442 sec(arctan(x)*arcsin(x))=1+12/4!*x^4-120/6!*x^6+17808/8!*x^8...

1, 0, 12, -120, 17808, -962880, 219945792, -31053369984, 10719320103168, -2908608708409344, 1441051026777725952, -637493975166202091520, 433239709928964325478400, -282573293205848764594176000

Offset

0,3

Links

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

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Sec[ArcTan[x]ArcSin[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Aug 10 2024 *)

Crossrefs

Sequence in context: A012373 A012620 A012564 * A262204 A037097 A337202

Adjacent sequences: A012439 A012440 A012441 * A012443 A012444 A012445

Keyword

sign

Author

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

Status

approved