1/4 the number of nX3 0..3 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

A186162

1/4 the number of nX3 0..3 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

Terms

    a(0) =1a(1) =48a(2) =702a(3) =14364a(4) =253341a(5) =4762206a(6) =87054174a(7) =1610684397a(8) =29645381115a(9) =546876640548

External references