57507domain: NAppears in sequencesNumber of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and column sum equal to 0 3 5 6 or 7 and every 3X3 diagonal and antidiagonal sum not equal to 0 3 5 6 or 7.at n=10A252142Number of oriented multidimensional n-ominoes with cell centers determining n-3 space.at n=6A355052