Base 3 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 239: | \[{3^{239}-1\over2}\] | 479 × 17209 × 43301964055635533333945745533106128044213<41> × 1507825692437133671959981388935564985777556063472074560073441273431<67> |