A023099 a(n) is least k such that k and 7k are anagrams in base n (written in base 10).

567, 7188, 1359, 140, 2574, 244, 778687, 28, 455, 8136, 8398, 30, 19950, 24640, 1183, 33, 828, 868, 925, 1989, 40977, 35042, 1421, 40, 41943, 1408, 4367, 2186880, 4830, 62472, 2405, 95, 3900, 168000, 382571, 154, 468270, 2398, 10005, 276, 649446, 2408