Expansion of e.g.f. tan(x)^2 (even powers only).

A009764

Expansion of e.g.f. tan(x)^2 (even powers only).

Terms

    a(0) =0a(1) =2a(2) =16a(3) =272a(4) =7936a(5) =353792a(6) =22368256a(7) =1903757312a(8) =209865342976

External references