A012339 Expansion of e.g.f.: sech(arcsin(x)*sin(x)).

1, 0, -12, 0, 6160, -120960, -30419136, 720079360, 289764450560, -67943999090688, -22346350979320832, 79039716551606272, -455312101897953210368, -1387404550704064289013760, -763348964181211012935499776, -349778941309176227928741642240

Offset

0,3

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..100

Example

1-12/4!*x^4+6160/8!*x^8-120960/10!*x^10...

Mathematica

With[{nn=40}, Take[CoefficientList[Series[Sech[ArcSin[x]Sin[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, May 17 2012 *)

Crossrefs

Sequence in context: A120954 A265087 A012337 * A012448 A012338 A012453

Adjacent sequences: A012336 A012337 A012338 * A012340 A012341 A012342

Keyword

sign

Author

Patrick Demichel

Extensions

Definition clarified by and more terms from Harvey P. Dale, May 17 2012

Status

approved