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

A238696

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

Terms

    a(0) =1a(1) =1a(2) =2a(3) =21a(4) =497a(5) =18508a(6) =3297933a(7) =2348121769

External references