Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 263: | \[{21^{263}-1\over20}\] | 399761 × 1192779167 × 11959744583<11> × 202742306849<12> × [23967225547914696108535367367720964465860583660349946891232834912200046936259509418803006821968488085636412691395523331381603031759144860639818372246631125557297231918536075894589318499186927281871889302187356303413289226516872152254921137617650873648375169773687766063279639715743975489420894815075602848683587<311>] |