Expansion of e.g.f. cos(tan(x)/cosh(x)), even terms only.

A009082

Expansion of e.g.f. cos(tan(x)/cosh(x)), even terms only.

Terms

    a(0) =1a(1) =-1a(2) =5a(3) =-157a(4) =3817a(5) =-257049a(6) =15886125a(7) =-1844058101a(8) =218349214545

External references