Number of n X n 0..2 arrays x(i,j) with each element horizontally or vertically next to at least one element with value 2-x(i,j).

A229840

Number of n X n 0..2 arrays x(i,j) with each element horizontally or vertically next to at least one element with value 2-x(i,j).

Terms

    a(0) =0a(1) =15a(2) =987a(3) =453837a(4) =1296261759

External references