Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 268: | \[{21^{268}-1\over20}\] | 22 × 11 × 13 × 17 × 269 × 4289 × 278051 × 324363426169571<15> × 12190216735350749<17> × 312929837239650768379490219650039<33> × 7433885411863948422879097872510769<34> × 71028332352256443443129296219339913167<38> × 43188774677058559319679599115492232913832013<44> × 202772476993530469121644814230122687390327067731486208636351160665437784301713<78> × 6340822630701755986496764672651013784788497018816491797711071984283214713483666711<82> |