Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 195: | \[{4^{195}-1\over3}\] | 3 × 7 × 11 × 31 × 79 × 131 × 151 × 331 × 2731 × 8191 × 107251 × 121369 × 409891 × 7623851 × 22366891 × 145295143558111<15> × 571403921126076957182161<24> × 134304196845099262572814573351<30> |