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A012462
Arcsinh(arctan(x)^2) = 2/2!*x^2 - 16/4!*x^4 + 248/6!*x^6 - 3456/8!*x^8 + ...
1
0, 2, -16, 248, -3456, -164448, 17537280, 5001348480, -3047690956800, 999150768960000, -194340969261158400, -28292890791044597760, 48811395838790000148480, -15658656394130132870062080, -19215487887156327014813859840, 37972554002174500707798919249920
OFFSET
0,2
MATHEMATICA
With[{nn=30}, Take[CoefficientList[Series[ArcSinh[ArcTan[x]^2], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, May 06 2013 *)
CROSSREFS
Sequence in context: A192325 A009233 A188560 * A012457 A138764 A009833
KEYWORD
sign
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
EXTENSIONS
Definition clarified by Harvey P. Dale, May 06 2013
STATUS
approved