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A013464 arctan(arctan(x)-arctanh(x))=-4/3!*x^3-1440/7!*x^7+35840/9!*x^9... 0
0, -4, 0, -1440, 35840, -7257600, 790732800, -208797388800, 48099557376000, -19670079356928000, 7390762646372352000, -4427057815048028160000, 2474680614543006105600000, -2020995311309719496294400000 (list; graph; refs; listen; history; text; internal format)
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

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Last modified August 12 13:34 EDT 2022. Contains 356077 sequences. (Running on oeis4.)