Base 3 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 201: | \[{3^{201}-1\over2}\] | 13 × 221101 × 1089421 × 441019876741<12> × 475384700124973<15> × 606888680894320302113812772385855126907748678398622467309<57> |