Base 5 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 131: | \[{5^{131}-1\over4}\] | 2621 × 23928199 × 34720241 × 16815642611861<14> × 250805666433416532678429525124977090318975999001796354124089<60> |