A009555 Expansion of e.g.f. sin(x)/cos(tan(x)) (odd powers only).

1, 2, 56, 2344, 168640, 18467712, 2863703168, 597301399296, 161295676067840, 54752864215838720, 22822208169450029056, 11459839362745219383296, 6823119037308555684642816, 4752955785723001118914052096

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..224

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Sin[x]/Cos[Tan[x]], {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Mar 08 2012 *)

Prog

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

Crossrefs

Sequence in context: A193476 A193475 A246001 * A054959 A206305 A325291

Adjacent sequences: A009552 A009553 A009554 * A009556 A009557 A009558

Keyword

nonn

Author

R. H. Hardin

Extensions

Extended and signs tested by Olivier Gérard, Mar 15 1997

Status

approved