491791680domain: NAppears in sequencesNumber of (n+1) X 2 0..3 arrays with equal numbers of 2 X 2 subblocks with sum over 6 and with sum under 6.at n=6A183750T(n,k) = number of (n+1) X (k+1) 0..3 arrays with equal numbers of 2 X 2 subblocks with sum over 6 and with sum under 6.at n=21A183756