Number of 4Xn 0..3 arrays with exactly floor(4Xn/2) elements equal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..3 order.

A222751

Number of 4Xn 0..3 arrays with exactly floor(4Xn/2) elements equal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..3 order.

Terms

    a(0) =0a(1) =685a(2) =125094a(3) =27397461a(4) =5989744766

External references