Half the number of (n+1) X 2 0..2 arrays with every 2 X 2 subblock having exactly one duplicate clockwise edge difference.

A209789

Half the number of (n+1) X 2 0..2 arrays with every 2 X 2 subblock having exactly one duplicate clockwise edge difference.

Terms

    a(0) =30a(1) =204a(2) =1380a(3) =9348a(4) =63300a(5) =428676a(6) =2902980a(7) =19659012a(8) =133130820a(9) =901562244a(10) =6105381060a(11) =41345652228a(12) =279992833860

External references