A013099 arctanh(arcsinh(x)+tan(x)) = 2*x+17/3!*x^3+873/5!*x^5+110127/7!*x^7...

2, 17, 873, 110127, 25968897, 9837102007, 5465752395569, 4187179894797967, 4229947817463760257, 5448264281798198909031, 8714522311726067909334321, 16946786732387040593899895551

Offset

0,1

Links

Table of n, a(n) for n=0..11.

Formula

a(n) ~ (2*n)! / r^(2*n+1), where r = 0.48741523182648... is the root of the equation log(sqrt(r^2+1)-r) = tan(r)-1. - Vaclav Kotesovec, Oct 24 2013

Mathematica

Table[n!*SeriesCoefficient[ArcTanh[ArcSinh[x]+Tan[x]], {x, 0, n}], {n, 1, 41, 2}] (* Vaclav Kotesovec, Oct 24 2013 *)

Crossrefs

Sequence in context: A167436 A015189 A012944 * A013060 A012988 A261535

Adjacent sequences: A013096 A013097 A013098 * A013100 A013101 A013102

Keyword

nonn

Author

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

Status

approved