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

A009095

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

Terms

    a(0) =1a(1) =-1a(2) =-3a(3) =-117a(4) =-903a(5) =-111529a(6) =687093a(7) =-320199453a(8) =44530596081a(9) =-254346923089

External references