A012819 E.g.f.: sec(sec(x)*sinh(x))=1+1/2!*x^2+21/4!*x^4+837/6!*x^6+60585/8!*x^8...

1, 1, 21, 837, 60585, 7048489, 1201350909, 282008557677, 87244033155153, 34402407033544657, 16843665951415524837, 10025536600336492439061, 7129473645057562412172537, 5969969671887834658217008633

Offset

0,3

Links

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

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Sec[Sec[x]Sinh[x]], {x, 0, nn}], x]Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Aug 19 2012 *)

Crossrefs

Sequence in context: A295845 A366301 A119414 * A297718 A296384 A296641

Adjacent sequences: A012816 A012817 A012818 * A012820 A012821 A012822

Keyword

nonn

Author

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

Extensions

Definition clarified by Harvey P. Dale, Aug 19 2012

Status

approved