Base 3 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 309: | \[{3^{309}-1\over2}\] | 13 × 1237 × 16069 × 6957596529882152968992225251835887181478451547013<49> × 749335951439164525377086885547523308245903253216162065126714079755203786701196169473212913<90> |