A012501 cos(cos(x)*arctan(x))=1-1/2!*x^2+21/4!*x^4-645/6!*x^6+34153/8!*x^8...

1, -1, 21, -645, 34153, -2966505, 380114493, -67244074989, 15717842398417, -4694489063253585, 1744673430747688805, -789702534539438543573, 427739642844597474379833, -273184203052102765688128825

Offset

0,3

Links

Table of n, a(n) for n=0..13.

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Cos[Cos[x]ArcTan[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Sep 06 2020 *)

Crossrefs

Sequence in context: A025752 A163032 A209264 * A027408 A177840 A297312

Adjacent sequences: A012498 A012499 A012500 * A012502 A012503 A012504

Keyword

sign

Author

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

Status

approved