Number of 4Xn 0..3 arrays with no more than floor(4Xn/2) elements equal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..3 order.

A222881

Number of 4Xn 0..3 arrays with no more than 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) =15a(1) =2150a(2) =443510a(3) =95867967a(4) =20978414941

External references