148304domain: NAppears in sequencesNumber of base 20 circular n-digit numbers with adjacent digits differing by 3 or less.at n=6A125330Number of (n+2) X (6+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 0 3 5 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 0 3 5 6 or 7.at n=19A252382