E.g.f. sec(arctan(x)^2) (even powers only).

A012466

E.g.f. sec(arctan(x)^2) (even powers only).

Terms

    a(0) =1a(1) =0a(2) =12a(3) =-480a(4) =37968a(5) =-4773120a(6) =878319552a(7) =-222512349696

External references