Half the number of (n+1)X(n+1) 0..2 arrays with every 2X2 subblock having two or four distinct clockwise edge differences.

A209504

Half the number of (n+1)X(n+1) 0..2 arrays with every 2X2 subblock having two or four distinct clockwise edge differences.

Terms

    a(0) =9a(1) =123a(2) =3906a(3) =290493a(4) =50798448a(5) =20934997854

External references