A012135 arcsin(arcsin(arctanh(x)))=x+4/3!*x^3+92/5!*x^5+5272/7!*x^7+567440/9!*x^9...

1, 4, 92, 5272, 567440, 98979200, 25530690624, 9147312168576, 4349983363258624, 2652517304182955008, 2018610268528861424640, 1875904660571518053251072, 2091013498538531655993561088

Offset

0,2

Links

Table of n, a(n) for n=0..12.

Mathematica

With[{nn=30}, Take[CoefficientList[Series[ArcSin[ArcSin[ArcTanh[x]]], {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* Harvey P. Dale, Mar 22 2019 *)

Crossrefs

Sequence in context: A322769 A012071 A012217 * A221287 A177411 A219891

Adjacent sequences: A012132 A012133 A012134 * A012136 A012137 A012138

Keyword

nonn

Author

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

Status

approved