2552850domain: NAppears in sequencesNumber of n X 3 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 1 0 and 1 1 1 vertically.at n=18A208496Number of n X 2 0..2 arrays avoiding 11 horizontally, 22 vertically and 00 diagonally or antidiagonally.at n=9A229374