Expansion of e.g.f. cos(x)*cos(tan(x)), even powers only.

A009099

Expansion of e.g.f. cos(x)*cos(tan(x)), even powers only.

Terms

    a(0) =1a(1) =-2a(2) =0a(3) =-8a(4) =192a(5) =20480a(6) =1837696a(7) =187743488a(8) =22698672128

External references