A012039 sinh(sin(arcsinh(x))) = x-1/3!*x^3+1/5!*x^5+111/7!*x^7-9407/9!*x^9...

1, -1, 1, 111, -9407, 957791, -131065791, 23876150351, -5645293077119, 1689130316350143, -625455343415905919, 281176376077651011119, -150982531394396522439999, 95493861079696805301099551

Offset

0,4

Links

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

Formula

a(n) ~ (-1)^n * cos(sinh(Pi/2)) * cosh(Pi/2) * 2^(2*n+1) * n^(2*n) / exp(2*n). - Vaclav Kotesovec, Oct 30 2013

Mathematica

Table[n!*SeriesCoefficient[Sinh[Sin[ArcSinh[x]]], {x, 0, n}], {n, 1, 40, 2}] (* Vaclav Kotesovec, Oct 30 2013 *)
With[{nn=30}, Take[CoefficientList[Series[Sinh[Sin[ArcSinh[x]]], {x, 0, nn}], x] Range[ 0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Mar 18 2023 *)

Crossrefs

Sequence in context: A232080 A332914 A129051 * A286117 A286083 A286731

Adjacent sequences: A012036 A012037 A012038 * A012040 A012041 A012042

Keyword

sign

Author

Patrick Demichel (patrick.demichel(AT)hp.com)

Status

approved