A009617 Expansion of tanh(tan(x))*sin(x)/2.

1, 116, 202576, 1557978176, 34206677698816, 1706222428480541696, 167325183704890858786816, 29168516299952885066683006976, 8389219957754997383106354075467776

Offset

0,2

Links

Table of n, a(n) for n=0..8.

Mathematica

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

Crossrefs

Cf. A012671.

Sequence in context: A296360 A035814 A284377 * A201728 A009687 A373582

Adjacent sequences: A009614 A009615 A009616 * A009618 A009619 A009620

Keyword

nonn

Author

R. H. Hardin

Extensions

Extended and signs tested 03/97.

Status

approved