Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
373: | \[2^{373}-1\] | 25569151 × 752440346497356983142327449546457327748644897934114291899411428982990336039662496766303354959577078458241<105> |