Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 511: | \[2^{511}-1\] | 127 × 439 × 2298041 × 15212471 × 9361973132609<13> × 144780974187086260903935034761413745643636578290924150417<57> × 2537599745025519134156761164267591913521835535529224725592538658153<67> |