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A012443
sech(arctan(x)*arcsin(x))=1-12/4!*x^4+120/6!*x^6-1008/8!*x^8...
0
1, 0, -12, 120, -1008, -45120, -11491392, 1378925184, -443544192768, 53698137606144, -32840379055537152, 7093049054642411520, -6636093887068155801600, 2065820944848385959936000
OFFSET
0,3
MATHEMATICA
With[{nn=30}, Take[CoefficientList[Series[Sech[ArcTan[x]ArcSin[x]], {x, 0, nn}], x]Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, May 01 2012 *)
CROSSREFS
Sequence in context: A268634 A061506 A059155 * A012274 A009035 A009140
KEYWORD
sign
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
STATUS
approved