A013102 Expansion of e.g.f: sech(arcsinh(x)+tan(x)).

1, -4, 72, -3414, 304696, -43757114, 9229955724, -2685455642198, 1030584093889104, -504321546504212914, 306492028524272596724, -226465717137080425353646, 199935485865217931345463224

Offset

0,2

Links

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

Example

1-4/2!*x^2+72/4!*x^4-3414/6!*x^6...

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Sech[ArcSinh[x]+Tan[x]], {x, 0, nn}], x]Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, May 17 2012 *)

Crossrefs

Sequence in context: A012947 A203535 A013066 * A224900 A012995 A076744

Adjacent sequences: A013099 A013100 A013101 * A013103 A013104 A013105

Keyword

sign

Author

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

Extensions

Definition clarified by Harvey P. Dale, May 17 2012

Status

approved