Expansion of e.g.f. tanh(x*tan(x/2)) (even powers only).

A296853

Expansion of e.g.f. tanh(x*tan(x/2)) (even powers only).

Terms

    a(0) =0a(1) =1a(2) =1a(3) =-27a(4) =-403a(5) =8345a(6) =688473a(7) =-208019a(8) =-3189211931a(9) =-162605047455

External references