Base 28 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 49: | \[{28^{49}-1\over27}\] | 113 × 197 × 2155609 × 4422461 × 319343666713<12> × 44498235948084746667439513476081194102813<41> |