A009687 Expansion of e.g.f. tan(sinh(x)*sin(x))/2 in odd powers of x^2.

1, 116, 221776, 2035313216, 57114906593536, 3831406959743783936, 525282700343846052745216, 132012923141044737907744587776, 56143990156951992731353775556591616, 38005061403111079268112619476719676686336, 39010496884020339788347064320442556327459291136

Offset

0,2

Links

Andrew Howroyd, Table of n, a(n) for n = 0..100

Example

x^2/2! + 116*x^6/6! + 221776*x^10/10! + 2035313216*x^14/14! ...

Mathematica

Tan[ Sinh[ x ]*Sin[ x ] ]/2 (* [ x^(4n+2) ] *)

Crossrefs

Cf. A024347.

Sequence in context: A284377 A009617 A201728 * A373582 A050660 A176568

Adjacent sequences: A009684 A009685 A009686 * A009688 A009689 A009690

Keyword

nonn

Author

R. H. Hardin

Extensions

Extended and signs tested 03/97.

a(9) onwards by Andrew Howroyd, Jan 12 2025

Status

approved