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

A003711

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

Terms

    a(0) =1a(1) =-1a(2) =9a(3) =-177a(4) =6097a(5) =-325249a(6) =24807321a(7) =-2558036145a(8) =342232522657

External references