Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
501: | \[2^{501}-1\] | 7 × 2349023 × 25129004796912072003423103<26> × 79638304766856507377778616296087448490695649<44> × 198950585925702911694795949136325395391616590334589163147577781735447402953<75> |