Base 7 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 107: | \[{7^{107}-1\over6}\] | 227109283745807808529<21> × 1620221568881364582821<22> × 1206506689449517154664984054683391885701717268373<49> |