Expansion of e.g.f. arctan(arctan(x)*arctan(x)) (even powers only).

A012459

Expansion of e.g.f. arctan(arctan(x)*arctan(x)) (even powers only).

Terms

    a(0) =0a(1) =2a(2) =-16a(3) =128a(4) =9984a(5) =-1444608a(6) =105185280a(7) =11495516160

External references