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

A009109

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

Terms

    a(0) =1a(1) =-2a(2) =16a(3) =-328a(4) =12160a(5) =-721280a(6) =62638720a(7) =-7495723264

External references