G.f.: exp( Sum_{n>=1} A002426(n^2) * x^n/n ), where A002426 is the central trinomial coefficients.

A225604

G.f.: exp( Sum_{n>=1} A002426(n^2) * x^n/n ), where A002426 is the central trinomial coefficients.

Terms

    a(0) =1a(1) =1a(2) =10a(3) =1056a(4) =1300253a(5) =16436676927

External references