6845784domain: NAppears in sequencesRestricted permutations.at n=23A000382Numbers k such that k and k^2 use only the digits 4, 5, 6, 7 and 8.at n=44A137140Numbers n such that the decimal expansions of both n and n^2 have 4 as the digit with the smallest value and 8 as the digit with the largest value.at n=17A254071