A009553 Expansion of e.g.f. sin(x)/cos(sin(x)) (odd powers only).

1, 2, -4, -176, -1712, 66912, 4737344, 53926656, -18559434496, -1869838374400, 35429689535488, 36301265658269696, 4137398544580202496, -569857298193726644224, -297369786811582548131840

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..248

Mathematica

With[{nmax = 50}, CoefficientList[Series[Sin[x]/Cos[Sin[x]], {x, 0, nmax}], x]*Range[0, nmax - 1]!][[2 ;; ;; 2]] (* G. C. Greubel, Jan 20 2018 *)

Prog

(PARI) x='x+O('x^50); v=Vec(serlaplace(sin(x)/cos(sin(x)))); vector((#v-1)\2 , n, v[2*n-1]) // G. C. Greubel, Jan 20 2018

Crossrefs

Sequence in context: A023171 A018595 A260900 * A012371 A009815 A012693

Adjacent sequences: A009550 A009551 A009552 * A009554 A009555 A009556

Keyword

sign

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved