A012460 cos(arctan(x)^2)=1-12/4!*x^4+480/6!*x^6-27888/8!*x^8...

1, 0, -12, 480, -27888, 2353920, -274245312, 41974872576, -8068087373568, 1860842339721216, -486190504963034112, 129225947748233994240, -22917287813817561968640, -13673939410058068058112000

Offset: 0

Author

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

Keywords

• sign

Programs

Mathematica

With[{nn=30},Take[CoefficientList[Series[Cos[ArcTan[x]^2],{x,0,nn}],x] Range[0,nn]!,{1,-1,2}]] (* Harvey P. Dale, Oct 07 2016 *)

Extensions

Definition clarified by Harvey P. Dale, Oct 07 2016