Number of (n+1)X3 0..3 arrays with every 2 X 2 subblock having the number of clockwise edge increases equal to the number of counterclockwise edge increases in its adjacent leftward and upward neighbors.

A205636

Number of (n+1)X3 0..3 arrays with every 2 X 2 subblock having the number of clockwise edge increases equal to the number of counterclockwise edge increases in its adjacent leftward and upward neighbors.

Terms

    a(0) =2320a(1) =28724a(2) =377568a(3) =5079336a(4) =69574220a(5) =962953968a(6) =13444055224a(7) =188823193784

External references