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A013465
cos(arctan(x)-arctanh(x))=1-160/6!*x^6-691200/10!*x^10+3942400/12!*x^12...
0
1, 0, 0, -160, 0, -691200, 3942400, -14125363200, 295206912000, -902471385088000, 43911376404480000, -140627264197754880000, 12856220870209699840000, -45500991975079280640000000
OFFSET
0,4
MATHEMATICA
With[{nn=30}, Take[CoefficientList[Series[Cos[ArcTan[x]-ArcTanh[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Ray Chandler, Nov 29 2016 *)
CROSSREFS
Sequence in context: A224430 A013454 A013455 * A013466 A376899 A060675
KEYWORD
sign
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
STATUS
approved