Base 5 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 88: | \[{5^{88}-1\over4}\] | 23 × 3 × 13 × 23 × 67 × 89 × 313 × 5281 × 12207031 × 1030330938209<13> × 9080418348371887359375390001<28> |