Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 258: | \[{4^{258}-1\over3}\] | 3 × 5 × 7 × 13 × 173 × 431 × 1033 × 9719 × 17029 × 46957 × 101653 × 500177 × 2099863 × 1591582393 × 1759217765581<13> × 2932031007403<13> × 15686603697451<14> × 96758771543686753<17> × 5951631966296685834686149<25> × 11053036065049294753459639<26> |