107777600domain: NAppears in sequencesNumbers k such that k and k^2 use only the digits 0, 1, 6 and 7.at n=12A136875Numbers k such that k and k^2 use only the digits 0, 1, 6, 7 and 8.at n=38A136876Numbers k such that k and k^2 use only the digits 0, 1, 6, 7 and 9.at n=22A136877