1/4 the number of nX6 0..3 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

A186165

1/4 the number of nX6 0..3 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

Terms

    a(0) =19a(1) =14748a(2) =4762206a(3) =1899336597a(4) =704281652979

External references