Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 296: | \[{21^{296}-1\over20}\] | 23 × 11 × 13 × 17 × 149 × 593 × 1481 × 31081 × 97241 × 1681762703 × 17515714824521<14> × 509348639343937<15> × 7995105693353508392600118377453099<34> × 379919184478057330357419845346252603881265273961<48> × 1788811503934407101186498308824780458046366903126234228620483937887212343860808538302796253<91> × 1899232502463611102338058672221678444532420442509607228961451036126583737448812560160009066892343663131266026084699230022034042173977743690432785418890712336593<160> |