A009085 Expansion of e.g.f. cos(tanh(sin(x))), even powers only.

1, -1, 13, -373, 19097, -1522409, 174263717, -27072485469, 5477315064625, -1398343023229393, 439386703590146365, -166541598232670049093, 74891796652158938855881, -39404384075265527597485241

Offset

0,3

Links

G. C. Greubel, Table of n, a(n) for n = 0..230

Maple

seq(coeff(series(factorial(n)*cos(tanh(sin(x))), x, n+1), x, n), n=0..30, 2); # Muniru A Asiru, Jul 25 2018

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Cos[Tanh[Sin[x]]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Nov 20 2015 *)

Prog

(PARI) x='x+O('x^50); v=Vec(serlaplace(cos(tanh(sin(x))))); vector(#v\2, n, v[2*n-1]) \\ G. C. Greubel, Jul 25 2018

Crossrefs

Sequence in context: A280796 A183472 A009040 * A012013 A082403 A171656

Adjacent sequences: A009082 A009083 A009084 * A009086 A009087 A009088

Keyword

sign

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Prior Mathematica program replaced by Harvey P. Dale, Nov 20 2015

Status

approved