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

A009751

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

Terms

    a(0) =0a(1) =2a(2) =8a(3) =48a(4) =2176a(5) =72704a(6) =2567168a(7) =320538624a(8) =23648567296

External references