A009559 Expansion of e.g.f. sin(x)/cosh(tan(x)) (odd powers only).

1, -4, -4, 104, 5392, 167936, 1592384, -401669248, -50456008448, -2742470413312, 310319594802176, 116183782320392192, 12985923007223566336, -3777809306960427778048, -2961060938622580774715392

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..240

Mathematica

With[{nmax = 50}, CoefficientList[Series[Sin[x]/Cosh[Tan[x]], {x, 0, nmax}], x]*Range[0, nmax - 1]!][[2 ;; ;; 2]] (* G. C. Greubel, Jan 21 2018 *)

Prog

(PARI) x='x+O('x^50); v=Vec(serlaplace(sin(x)/cosh(tan(x)))); vector((#v-1)\2 , n, v[2*n-1]) \\ G. C. Greubel, Jan 21 2018

Crossrefs

Sequence in context: A092209 A068337 A009534 * A163196 A219453 A283453

Adjacent sequences: A009556 A009557 A009558 * A009560 A009561 A009562

Keyword

sign

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved