A012570 sech(sinh(x)*cos(x))=1-1/2!*x^2+13/4!*x^4-277/6!*x^6+12185/8!*x^8...

1, -1, 13, -277, 12185, -840489, 84759717, -11842313277, 2175505004849, -510170676389457, 148514509335632701, -52567147994554822501, 22230968162996350213321, -11070593880057710100740473

Offset

0,3

Links

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

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Sech[Sinh[x]Cos[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Jul 28 2021 *)

Crossrefs

Sequence in context: A295550 A320336 A133284 * A256044 A160294 A092145

Adjacent sequences: A012567 A012568 A012569 * A012571 A012572 A012573

Keyword

sign

Author

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

Status

approved