Expansion of e.g.f. cos(tanh(x)*tan(x)) (only powers that are multiples of 4).

A009094

Expansion of e.g.f. cos(tanh(x)*tan(x)) (only powers that are multiples of 4).

Terms

    a(0) =1a(1) =-12a(2) =-4592a(3) =-6274752a(4) =18138366208

External references