Expansion of tanh(tan(x))*tan(x).

A009812

Expansion of tanh(tan(x))*tan(x).

Terms

    a(0) =0a(1) =2a(2) =8a(3) =48a(4) =384a(5) =18944a(6) =2364416a(7) =271337472a(8) =29986947072

External references