Number of (n+1)X(n+1) 0..1 arrays with every 2X2 subblock having a single 1 or two 1s on the same edge or main diagonally.

A251284

Number of (n+1)X(n+1) 0..1 arrays with every 2X2 subblock having a single 1 or two 1s on the same edge or main diagonally.

Terms

    a(0) =9a(1) =71a(2) =822a(3) =18924a(4) =577942a(5) =39473392a(6) =3232216177a(7) =648994836940

External references