A024289 Expansion of e.g.f. of tan(tan(x))*x/2 (even powers only).

0, 1, 8, 216, 11584, 1019520, 132672000, 23886564352, 5679985229824, 1723355387559936, 649567394309734400, 297722967189644902400, 163056718857998098759680, 105162437290880582018924544

Offset

0,3

Links

Table of n, a(n) for n=0..13.

Formula

a(n) = A009700(n) / 2.

Mathematica

Tan[ Tan[ x ] ]*x/2 (* Even Part *)

Crossrefs

Equals A009700/2.

Sequence in context: A362073 A009072 A002897 * A009106 A000442 A268471

Adjacent sequences: A024286 A024287 A024288 * A024290 A024291 A024292

Keyword

nonn

Author

R. H. Hardin

Extensions

Extended and signs tested Mar 1997.

Status

approved