A009568 Expansion of e.g.f.: sinh(log(1+sinh(x))).

0, 1, -1, 4, -16, 91, -616, 4894, -44416, 453541, -5145856, 64222984, -874402816, 12897183391, -204862698496, 3486535686274, -63292764553216, 1220795601029641, -24931903045697536, 537463528325234764, -12196043454064623616, 290588368323926512291, -7253387436695186046976

Offset

0,4

Links

G. C. Greubel, Table of n, a(n) for n = 0..438

Formula

a(2*n) = A006154(2*n)/2, n>0. - Ralf Stephan, Apr 29 2004

Mathematica

With[{nn=20}, CoefficientList[Series[Sinh[Log[1+Sinh[x]]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Dec 08 2017 *)

Prog

(PARI) x='x+O('x^30); concat([0], Vec(serlaplace( sinh(log(1+sinh(x)))))) \\ G. C. Greubel, Jan 21 2018

Crossrefs

Sequence in context: A376797 A221818 A331648 * A139155 A003762 A143501

Adjacent sequences: A009565 A009566 A009567 * A009569 A009570 A009571

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Prior Mathematica program replaced and definition clarified by Harvey P. Dale, Dec 08 2017

Terms a(20) to a(22) added by G. C. Greubel, Jan 21 2018

Status

approved