19659012domain: NAppears in sequencesHalf the number of (n+1) X 2 0..2 arrays with every 2 X 2 subblock having exactly one duplicate clockwise edge difference.at n=7A209789T(n,k)=Half the number of (n+1)X(k+1) 0..2 arrays with every 2X2 subblock having exactly one duplicate clockwise edge difference.at n=28A209796