Expansion of e.g.f. sec(arctanh(x)*cos(x)), only even powers.

A012748

Expansion of e.g.f. sec(arctanh(x)*cos(x)), only even powers.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =25a(4) =3617a(5) =340145a(6) =40490657a(7) =7034559753

External references