A012799 sec(sec(x)*tan(x))=1+1/2!*x^2+25/4!*x^4+1177/6!*x^6+98705/8!*x^8...

1, 1, 25, 1177, 98705, 13250769, 2607761385, 707007382057, 252591724020385, 115013019820614177, 65019184411131252025, 44683093185748102178361, 36687179790948560158256945, 35468646820376578609567141873

Offset

0,3

Links

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

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Sec[Sec[x]Tan[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Sep 11 2023 *)

Crossrefs

Sequence in context: A123204 A012508 A112102 * A120694 A012809 A014769

Adjacent sequences: A012796 A012797 A012798 * A012800 A012801 A012802

Keyword

nonn

Author

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

Status

approved