A009378 Expansion of log(1+tan(x)*sinh(x)).

0, 2, 0, 22, 280, 5402, 515460, 11703382, 2688141040, 146635350962, 34251754225020, 4629204580980142, 993794187704175400, 265705552906954222922, 63184407507496166760180

Offset

0,2

Links

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

Formula

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

Mathematica

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

Crossrefs

Sequence in context: A293938 A254042 A368014 * A106708 A138551 A133490

Adjacent sequences: A009375 A009376 A009377 * A009379 A009380 A009381

Keyword

nonn

Author

R. H. Hardin

Extensions

Extended and signs tested by Olivier Gérard, Mar 15 1997

Status

approved