1/20 of the number of (n+1) X 4 0..4 arrays with every 2 X 2 subblock strictly increasing clockwise or counterclockwise with one decrease.

A183713

1/20 of the number of (n+1) X 4 0..4 arrays with every 2 X 2 subblock strictly increasing clockwise or counterclockwise with one decrease.

Terms

    a(0) =12a(1) =54a(2) =224a(3) =950a(4) =4012a(5) =16964a(6) =71712a(7) =303170a(8) =1281664a(9) =5418314a(10) =22906232a(11) =96837444a(12) =409385940a(13) =1730703022a(14) =7316648160a(15) =30931557950a(16) =130764969444a(17) =552816553732

External references