Base 3 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 278: | \[{3^{278}-1\over2}\] | 22 × 1669 × 5430731 × 26436515641<11> × 1113626506203380968993<22> × 17735794220172313692220944999595159<35> × 115215201111546538317696820901417129607616709798043944747<57> |