Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 306: | \[{21^{306}-1\over20}\] | 2 × 11 × 19 × 37 × 103 × 199 × 307 × 421 × 463 × 613 × 11969 × 15607 × 38047 × 80031547 × 85775383 × 114089969144083169<18> × 625770304116639832567<21> × 1502097124754084594737<22> × 34098331055594280023053<23> × 847586878961383719143557147<27> × 812747902414376177310556049257081<33> × 51233569124705721849500009982296618143<38> × 20813096623337757798888685318376525907607<41> × 379395745875808971155324352649338339586035997<45> × 34356186698231953283360965178078588736506591800565430317349977053251974794072110645024944083<92> |