A009098 Expansion of e.g.f. cos(x)*cos(sinh(x)), even powers only.

1, -2, 4, 32, -48, -5600, -85568, 533504, 85827840, 3149702656, 27282224128, -5424499154944, -496815684169728, -22408107489910784, 247218592921600000, 170684586701783564288, 20039831043212444762112

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..250

Mathematica

With[{nn=40}, Take[CoefficientList[Series[Cos[x]*Cos[Sinh[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Sep 10 2017 *)

Prog

(PARI) x='x+O('x^50); v=Vec(serlaplace(cos(x)*cos(sinh(x)))); vector(#v\2, n, v[2*n-1]) \\ G. C. Greubel, Jul 26 2018

Crossrefs

Sequence in context: A293760 A101575 A197099 * A192387 A320624 A133127

Adjacent sequences: A009095 A009096 A009097 * A009099 A009100 A009101

Keyword

sign

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Prior Mathematica program replaced by Harvey P. Dale, Sep 10 2017

Status

approved