Base 7 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 91: | \[{7^{91}-1\over6}\] | 29 × 4733 × 7304123737<10> × 16148168401<11> × 231410451435538144122809<24> × 3565837331172073232378945297<28> |