1/4 the number of (n+1)X6 0..3 arrays with every 2X2 subblock having exactly two distinct clockwise edge differences.

A209550

1/4 the number of (n+1)X6 0..3 arrays with every 2X2 subblock having exactly two distinct clockwise edge differences.

Terms

    a(0) =603a(1) =16582a(2) =425803a(3) =11226644a(4) =294738262a(5) =7751834609a(6) =203828058161

External references