Base 5 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 217: | \[{5^{217}-1\over4}\] | 1861 × 8681 × 19531 × 1828916514769<13> × 625552508473588471<18> × 32880066613669997886452062118468047118941660083643595052667236211020251230387736755622191604390430911142652289<110> |