Base 5 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 153: | \[{5^{153}-1\over4}\] | 19 × 31 × 409 × 829 × 4591 × 90271 × 317731 × 26481241 × 466344409 × 654652168021<12> × 360143672909416579<18> × 285963691592722767421088565601855215949<39> |