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

A210149

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

Terms

    a(0) =57a(1) =820a(2) =11783a(3) =169343a(4) =2433709a(5) =34976109a(6) =502659771a(7) =7223984325a(8) =103819625131

External references