Number of nX4 0..3 arrays with values 0..3 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.

A199145

Number of nX4 0..3 arrays with values 0..3 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.

Terms

    a(0) =2a(1) =65a(2) =2453a(3) =125468a(4) =6235011a(5) =316561994a(6) =15958823113a(7) =806680624447

External references