Number of nX4 0..3 arrays with values 0..3 introduced in row major order and each element equal to no more than two horizontal and vertical neighbors.

A200797

Number of nX4 0..3 arrays with values 0..3 introduced in row major order and each element equal to no more than two horizontal and vertical neighbors.

Terms

    a(0) =15a(1) =2614a(2) =583813a(3) =132636590a(4) =30147154218

External references