A013464 arctan(arctan(x)-arctanh(x))=-4/3!*x^3-1440/7!*x^7+35840/9!*x^9...

0, -4, 0, -1440, 35840, -7257600, 790732800, -208797388800, 48099557376000, -19670079356928000, 7390762646372352000, -4427057815048028160000, 2474680614543006105600000, -2020995311309719496294400000

Offset

0,2

Links

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

Mathematica

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

Crossrefs

Sequence in context: A012502 A130105 A013463 * A331582 A306819 A336327

Adjacent sequences: A013461 A013462 A013463 * A013465 A013466 A013467

Keyword

sign

Author

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

Status

approved