A009718 Expansion of tan(tanh(x))*x.

0, 2, 0, -48, 896, -1280, -1317888, 113985536, -5662048256, -173996310528, 103038851481600, -18151624725757952, 1834297840675848192, 53334014587534573568, -66117477689491873333248

Offset

0,2

Links

Table of n, a(n) for n=0..14.

Mathematica

Tan[ Tanh[ x ] ]*x (* Even Part *)

Crossrefs

Sequence in context: A097173 A392128 A009493 * A198799 A156501 A012420

Adjacent sequences: A009715 A009716 A009717 * A009719 A009720 A009721

Keyword

sign

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved