E.g.f.: Shw(x) / Chw(x), where Chw(x) = Sum_{n>=0} (2n+1)^(2n-1) * x^(2n)/(2n)! and Shw(x) = Sum_{n>=0} (2n+2)^(2n) * x^(2n+1)/(2n+1)!, with zero coefficients omitted.

A215890

E.g.f.: Shw(x) / Chw(x), where Chw(x) = Sum_{n>=0} (2*n+1)^(2*n-1) * x^(2*n)/(2*n)! and Shw(x) = Sum_{n>=0} (2*n+2)^(2*n) * x^(2*n+1)/(2*n+1)!, with zero coefficients omitted.