Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 427: | \[2^{427}-1\] | 127 × 33282089 × 2305843009213693951<19> × 35560193412972319062061768261639727517478499914167548496031688280584977077562191671059223282469465959<101> |