Number of n X n 0..3 arrays with no element equal to another at a city block distance of exactly two, and new values 0..3 introduced in row major order.

A222833

Number of n X n 0..3 arrays with no element equal to another at a city block distance of exactly two, and new values 0..3 introduced in row major order.

Terms

    a(0) =1a(1) =7a(2) =72a(3) =600a(4) =4032a(5) =24576a(6) =138240a(7) =743424a(8) =3833856a(9) =19267584a(10) =94371840a(11) =454557696

External references