Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 512: | \[{21^{512}-1\over20}\] | 29 × 11 × 13 × 17 × 257 × 641 × 1217 × 1409 × 2689 × 31873 × 37889 × 62897 × 97241 × 300673 × 527489 × 54766081 × 6857635489<10> × 70660081537<11> × 1649000397313<13> × 47364380213310995446855681<26> × 14437340972205028628646350918657<32> × 17505576891450841829489878762926790845953<41> × 1023263388750334684164671319051311082339521<43> × 242055625097457531000185232276713458675446736812859343682689<60> × 10578191969088656642408778452194753320544672852280266940970265834953323387729579553681207378692509046017<104> × [3114416380283196989601467180092632227304587187798493466640394697314827110926147856289485517275449410676384442932571030583513781429459059212635351956205164371940690570351715858208513246795890979559417122501795291389086057527103297936457108651762758109085786460122859979279576488237569<283>] |