A009549 Expansion of e.g.f. sin(x)*sin(tanh(x)) (even powers only).

0, 2, -16, 288, -9920, 541184, -42274816, 4449451776, -605255720960, 103187353223168, -21528004660707328, 5391886872902762496, -1595781555670951657472, 550728986895462989103104

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..239

Mathematica

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

Prog

(PARI) x='x+O('x^50); v=Vec(serlaplace(sin(x)*sin(tanh(x)))); concat([0], vector(#v\2, n, v[2*n-1])) \\ G. C. Greubel, Jan 20 2018

Crossrefs

Sequence in context: A123744 A136796 A055546 * A254744 A009795 A182562

Adjacent sequences: A009546 A009547 A009548 * A009550 A009551 A009552

Keyword

sign

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved