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

A009273

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

Terms

    a(0) =1a(1) =2a(2) =4a(3) =-24a(4) =400a(5) =-5600a(6) =-103872a(7) =26975872a(8) =-3438685952a(9) =417995260416

External references