A009745 Expansion of e.g.f tan(x)*sinh(sin(x)), even powers only.

0, 2, 8, 48, 1728, 61184, 3107840, 235484928, 22794670080, 2824580218880, 435346731352064, 81496599519363072, 18232624878580924416, 4803148337754795474944, 1471655716879344564174848

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..242

Formula

a(n) ~ (2*n)! * (exp(1) - exp(-1)) * (2/Pi)^(2*n+1). - Vaclav Kotesovec, Jan 23 2015

Mathematica

nn = 20; Table[(CoefficientList[Series[Sinh[Sin[x]]*Tan[x], {x, 0, 2*nn}], x] * Range[0, 2*nn]!)[[n]], {n, 1, 2*nn+1, 2}] (* Vaclav Kotesovec, Jan 23 2015 *)

Prog

(PARI) x='x+O('x^50); v=Vec(serlaplace(tan(x)*sinh(sin(x)))); concat([0], vector(#v\2, n, v[2*n-1])) \\ G. C. Greubel, Feb 12 2018

Crossrefs

Sequence in context: A079802 A009741 A322309 * A009751 A356658 A279239

Adjacent sequences: A009742 A009743 A009744 * A009746 A009747 A009748

Keyword

nonn

Author

R. H. Hardin

Extensions

Extended and signs tested by Olivier Gérard, Mar 15 1997

Status

approved