A009498 Expansion of sin(sinh(x)/cos(x)).

1, 3, -3, -1113, -77063, -5509845, -430006731, -33282260529, -1454472663311, 448480622503635, 254015086363619949, 101877925964986614135, 39296835590108099513833, 15506451718661316904568571

Offset

0,2

Links

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

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Sin[Sinh[x]/Cos[x]], {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Feb 25 2023 *)

Crossrefs

Sequence in context: A138662 A009011 A291095 * A076253 A081174 A292832

Adjacent sequences: A009495 A009496 A009497 * A009499 A009500 A009501

Keyword

sign

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Previous Mathematica program replaced by Harvey P. Dale, Feb 25 2023

Status

approved