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

A009105

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

Terms

    a(0) =1a(1) =0a(2) =4a(3) =56a(4) =2192a(5) =128448a(6) =11141824a(7) =1332816512a(8) =210250492160

External references