Base 7 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 209: | \[{7^{209}-1\over6}\] | 419 × 1123 × 293459 × 4534166740403<13> × 8048541876545647951<19> × 13963143622655349298631892676568927428058929373643146886475251015395202933516873297677437095819612756489586524006900292844035629339199<134> |