Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
231: | \[2^{231}-1\] | 72 × 23 × 89 × 127 × 337 × 463 × 599479 × 581283643249112959<18> × 4982397651178256151338302204762057<34> |