A013004 tanh(arctan(x)+tan(x))=2*x-16/3!*x^3+552/5!*x^5-41984/7!*x^7...

2, -16, 552, -41984, 5530752, -1117490944, 320707001344, -123976597878784, 62093009928880128, -39107324387947577344, 30249801409640561901568, -28190352567614102755082240, 31151946815227412004856659968

Offset

0,1

Links

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

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Tanh[ArcTan[x]+Tan[x]], {x, 0, nn}], x] Range[0, nn-1]!, {2, -2, 2}]] (* Harvey P. Dale, Jan 28 2013 *)

Crossrefs

Sequence in context: A013087 A121271 A013136 * A012679 A012726 A013177

Adjacent sequences: A013001 A013002 A013003 * A013005 A013006 A013007

Keyword

sign

Author

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

Status

approved