1/3 the number of n X n 0..2 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

A185551

1/3 the number of n X n 0..2 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

Terms

    a(0) =0a(1) =5a(2) =224a(3) =58458a(4) =64354744a(5) =353403366772

External references