A012794 sech(sec(x)*arcsin(x))=1-1/2!*x^2-11/4!*x^4-85/6!*x^6+4457/8!*x^8...

1, -1, -11, -85, 4457, 456055, 19404317, -2130838749, -709981721647, -88561132771729, 8928572938556485, 8215826370826826011, 1643974395579178155321, -777302111773052397223705, -927256122029195944220743571, -491644215408419904657774637165

Offset

0,3

Links

Table of n, a(n) for n=0..15.

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Sech[Sec[x]ArcSin[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Mar 25 2015 *)

Crossrefs

Sequence in context: A082365 A344480 A320940 * A302954 A014917 A390530

Adjacent sequences: A012791 A012792 A012793 * A012795 A012796 A012797

Keyword

sign

Author

Patrick Demichel

Extensions

More terms from Harvey P. Dale, Mar 25 2015

Status

approved