A009088 Expansion of e.g.f. x*cos(tanh(x)), odd powers only.

1, -3, 45, -1239, 54873, -3577739, 322495173, -38370542175, 5817952885169, -1093812528874387, 249472828725529437, -67807763939709678951, 21642089202188444732425, -8010884242566625383028251

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..239

Maple

seq(coeff(series(factorial(n)*x*cos(tanh(x)), x, n+1), x, n), n=1..30, 2); # Muniru A Asiru, Jul 25 2018

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Cos[Tanh[x]]x, {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Nov 01 2011 *)

Prog

(PARI) x='x+O('x^60); v=Vec(serlaplace(x*cos(tanh(x)))); vector((#v-1)\2, n, v[2*n-1]) \\ G. C. Greubel, Jul 25 2018

Crossrefs

Sequence in context: A302106 A361046 A241242 * A245066 A352409 A187662

Adjacent sequences: A009085 A009086 A009087 * A009089 A009090 A009091

Keyword

sign

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved