1/3 the number of n X 7 0..2 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

A185557

1/3 the number of n X 7 0..2 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

Terms

    a(0) =21a(1) =13256a(2) =2792166a(3) =684657326a(4) =160107914496

External references