12333335domain: NAppears in sequencesNumbers k such that k^2 contains only digits {1,2,5}.at n=26A031153Numbers k such that k and k^2 use only the digits 1, 2, 3 and 5.at n=21A136973Numbers k such that the decimal expansions of both k and k^2 have 1 as smallest digit and 5 as largest digit.at n=27A256889