1155211domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumbers k such that k and k^2 use only the digits 1, 2, 3, 4 and 5.at n=43A136968Numbers k such that the decimal expansions of both k and k^2 have 1 as smallest digit and 5 as largest digit.at n=18A256889Prime numbersat n=89676