Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 156: | \[{4^{156}-1\over3}\] | 3 × 5 × 7 × 132 × 17 × 53 × 79 × 157 × 241 × 313 × 1249 × 1613 × 2731 × 3121 × 8191 × 21841 × 121369 × 858001 × 22366891 × 308761441 × 84159375948762099254554456081<29> |