Number of n X n 0..3 arrays with row sums 2*n and column sums 2*n.

A172748

Number of n X n 0..3 arrays with row sums 2*n and column sums 2*n.

Terms

    a(0) =1a(1) =3a(2) =55a(3) =8515a(4) =13130451a(5) =210668680701

External references