a(n) = Sum_{k=0..n} binomial(n^2 - k^2, n*k - k^2).

A245242

a(n) = Sum_{k=0..n} binomial(n^2 - k^2, n*k - k^2).

Terms

    a(0) =1a(1) =2a(2) =5a(3) =40a(4) =987a(5) =73026a(6) =15656191a(7) =9146092572

External references