Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 331: | \[2^{331}-1\] | 16937389168607<14> × 865118802936559<15> × 298542624980197463613767215333569428005686468835821253721796682625551919<72> |