a(n) = A002426(n^2), where A002426 is the central trinomial coefficients.

A225602

a(n) = A002426(n^2), where A002426 is the central trinomial coefficients.

Terms

    a(0) =1a(1) =1a(2) =19a(3) =3139a(4) =5196627a(5) =82176836301

External references