Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 425: | \[2^{425}-1\] | 31 × 601 × 1801 × 131071 × 9520972806333758431<19> × 2069237502716464794985816105550982396339012259800336045348830659287429006970383760001800897298401<97> |