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

A186160

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

Terms

    a(0) =0a(1) =7a(2) =702a(3) =751266a(4) =5033988714

External references