A009732 Expansion of tan(x)*cosh(sin(x)) (odd powers only).

1, 5, 21, 377, 13129, 537965, 34399197, 2946509729, 323564702737, 44888950379477, 7640931012615717, 1566846818139059657, 381021443277747203161, 108403869650402266171709

Offset

1,2

Links

Table of n, a(n) for n=1..14.

Formula

a(n) ~ (2*n-1)! * 4^n * (exp(1) + exp(-1)) / Pi^(2*n). - Vaclav Kotesovec, Jan 23 2015

Mathematica

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

Crossrefs

Sequence in context: A015461 A101694 A006109 * A009758 A143503 A144779

Adjacent sequences: A009729 A009730 A009731 * A009733 A009734 A009735

Keyword

nonn

Author

R. H. Hardin

Extensions

Extended and signs tested Mar 15 1997 by Olivier Gérard.

Offset changed to 1 by Vaclav Kotesovec, Jan 23 2015

Status

approved