1796636domain: NAppears in sequencesNumber of (n+1) X (n+1) 0..3 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4 (constant-stress 1 X 1 tilings).at n=15A235281Number of centrally symmetric Baxter permutations of length n.at n=19A383372