A013144 arctan(tanh(x)+arctan(x))=2*x-20/3!*x^3+1128/5!*x^5-158112/7!*x^7...

2, -20, 1128, -158112, 41334912, -17364051712, 10697958401024, -9087507664709632, 10179531541621604352, -14538540850131730563072, 25785525466844174964228096, -55601885971190702384095952896

Offset

0,1

Links

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

Mathematica

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

Crossrefs

Sequence in context: A015192 A012790 A273194 * A239642 A369679 A112359

Adjacent sequences: A013141 A013142 A013143 * A013145 A013146 A013147

Keyword

sign

Author

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

Status

approved