A012118 - OEIS

A012118

tanh(arcsin(arcsinh(x)))=x-2/3!*x^3+24/5!*x^5-664/7!*x^7+36096/9!*x^9...

1, -2, 24, -664, 36096, -3054336, 389859456, -67637286144, 15712242647040, -4624447960903680, 1704772464238264320, -762137182003035340800, 409146648871581200056320, -258451658825083238747013120

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

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

MATHEMATICA

With[{nn=30}, Take[CoefficientList[Series[Tanh[ArcSin[ArcSinh[x]]], {x, 0, nn}], x]Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Dec 02 2011 *)

CROSSREFS

Sequence in context: A123741 A302579 A012216 * A012375 A012750 A174997

Adjacent sequences: A012115 A012116 A012117 * A012119 A012120 A012121

KEYWORD

sign

AUTHOR

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

STATUS

approved