A009039 Expansion of E.g.f. cos(sin(tan(x))), even powers only.

1, -1, -3, 27, 2425, 143031, 8956533, 618394579, 46232494321, 3608163168111, 254307747662573, -15725973912655477, -32163339922362247575, -26444005741558393208281, -19705272022676306432282267

Offset

0,3

Links

G. C. Greubel, Table of n, a(n) for n = 0..237

Mathematica

With[{nmax = 60}, CoefficientList[Series[Cos[Sin[Tan[x]]], {x, 0, nmax}], x]*Range[0, nmax]!][[1 ;; -1 ;; 2]] (* G. C. Greubel, Jul 22 2018 *)

Prog

(PARI) x='x+O('x^60); v=Vec(serlaplace(cos(sin(tan(x))))); vector(#v\2, n, v[2*n-1]) \\ G. C. Greubel, Jul 22 2018

Crossrefs

Sequence in context: A184278 A158113 A078233 * A137092 A122215 A122217

Adjacent sequences: A009036 A009037 A009038 * A009040 A009041 A009042

Keyword

sign

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved