A013175 sin(arctanh(x)+arctan(x))=2*x-8/3!*x^3+80/5!*x^5-4160/7!*x^7...

2, -8, 80, -4160, 177920, -25548800, 2560563200, -702660608000, 129295622144000, -57197188186112000, 16886573106790400000, -10912577096233779200000, 4743735379760119808000000

Offset

0,1

Links

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

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Sin[ArcTanh[x]+ArcTan[x]], {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]] (* Ray Chandler, Nov 29 2016 *)

Crossrefs

Sequence in context: A229865 A134086 A297566 * A120820 A295600 A336252

Adjacent sequences: A013172 A013173 A013174 * A013176 A013177 A013178

Keyword

sign

Author

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

Status

approved