Even coefficients in expansion of e.g.f. cos(x)/sqrt(cos(2*x)).

A012085

Even coefficients in expansion of e.g.f. cos(x)/sqrt(cos(2*x)).

Terms

    a(0) =1a(1) =1a(2) =17a(3) =721a(4) =58337a(5) =7734241a(6) =1526099057a(7) =419784870961

External references