E.g.f. exp(tanh(x)^2) (even powers only).

A009277

E.g.f. exp(tanh(x)^2) (even powers only).

Terms

    a(0) =1a(1) =2a(2) =-4a(3) =-88a(4) =4496a(5) =-155488a(6) =675776a(7) =903834752a(8) =-178181918464

External references