A009159 Expansion of cosh(tan(x))*cos(x).

1, 0, 4, 56, 1744, 86208, 6199744, 608357504, 77889982720, 12588540708864, 2503565961032704, 600347512023062528, 170721835772956659712, 56780394898390577528832, 21828678118361789793746944

Offset

0,3

Links

Table of n, a(n) for n=0..14.

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Cosh[Tan[x]]*Cos[x], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Jul 28 2019 *)

Crossrefs

Sequence in context: A009563 A261747 A111849 * A013055 A243486 A322733

Adjacent sequences: A009156 A009157 A009158 * A009160 A009161 A009162

Keyword

nonn

Author

R. H. Hardin

Extensions

Extended and signs tested Mar 15 1997 by Olivier Gérard.

Previous Mathematica program replaced by Harvey P. Dale, Jul 28 2019

Status

approved