Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 284: | \[{4^{284}-1\over3}\] | 5 × 17 × 569 × 2273 × 228479 × 1433633 × 48544121 × 56409643 × 148587949 × 212885833 × 4999465853<10> × 5585522857<10> × 472287102421<12> × 13952598148481<14> × 561089862628529469701880307617682175171538701774485416358584106265670728689<75> |