Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 419: | \[2^{419}-1\] | 839 × 903780021613921<15> × 5800422716722833271214743<25> × 10287968884341772230096159036619433593<38> × 29919490848598531825060153417921002916701815927<47> |