Expansion of e.g.f. sec(x*tan(x/2)) (even powers only).

A296939

Expansion of e.g.f. sec(x*tan(x/2)) (even powers only).

Terms

    a(0) =1a(1) =0a(2) =3a(3) =15a(4) =644a(5) =17145a(6) =1124673a(7) =74115496a(8) =7730031915a(9) =921044459943

External references