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

A009072

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

Terms

    a(0) =1a(1) =0a(2) =-8a(3) =-216a(4) =-7552a(5) =-349568a(6) =-20281216a(7) =-1350879232a(8) =-84211707904a(9) =286327484416

External references