258080domain: NAppears in sequencesSite percolation series for 4.8 (bathroom tile) lattice.at n=41A120557Number of (1+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 0 2 3 6 or 7 and every 3X3 column and antidiagonal sum not equal to 0 2 3 6 or 7.at n=25A252533