Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 343: | \[2^{343}-1\] | 127 × 6073159 × 1428389887 × 62228099977<11> × 4432676798593<13> × 58961804474844164724814095915114338093146118248375213688557057<62> |