Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 111: | \[{4^{111}-1\over3}\] | 3 × 7 × 223 × 1777 × 3331 × 17539 × 321679 × 25781083 × 26295457 × 319020217 × 616318177 × 107775231312019<15> |