L.g.f.: Sum_{n>=1} x^n/n * Sum_{k=0..n} binomial(n^2, k*(n-k))*x^k = Sum_{n>=1} a(n)*x^n/n.

A207138

L.g.f.: Sum_{n>=1} x^n/n * Sum_{k=0..n} binomial(n^2, k*(n-k))*x^k = Sum_{n>=1} a(n)*x^n/n.

Terms

    a(0) =1a(1) =3a(2) =7a(3) =51a(4) =761a(5) =17913a(6) =688745a(7) =56611987a(8) =11405877739

External references