1/7 the number of nX4 0..6 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

A185407

1/7 the number of nX4 0..6 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

Terms

    a(0) =7a(1) =1848a(2) =279918a(3) =53808534a(4) =9560464068

External references