Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
283: | \[2^{283}-1\] | 9623 × 68492481833<11> × 23579543011798993222850893929565870383844167873851502677311057483194673<71> |