this is map of bases 2-36 in which last digit in number can be prime or a guarantee a super rectangle
Also those bases will end at: (only main) 2,4,8,16-256 3,9-243 5-250 6-216 7-245 10,15-300 12-288 14-294 18-324 20-400 (past 20 will be split in parts btw) 24-576 30-900 36-1296