1/4 the number of (n+1)X3 0..3 arrays with every 2X2 subblock having one or three distinct clockwise edge differences.

A210071

1/4 the number of (n+1)X3 0..3 arrays with every 2X2 subblock having one or three distinct clockwise edge differences.

Terms

    a(0) =313a(1) =7653a(2) =183628a(3) =4437262a(4) =107248254a(5) =2593403383a(6) =62718516080

External references