52515domain: NAppears in sequencesNumbers k such that k and k^2 use only the digits 1, 2, 5, 7 and 8.at n=11A137008Number of (n+2) X (1+2) 0..1 arrays with each 3 X 3 subblock having clockwise perimeter pattern 00000000 00000001 or 00001001.at n=9A259955