Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
371: | \[2^{371}-1\] | 127 × 743 × 2969 × 6361 × 69431 × 20394401 × 63781899287<11> × 204712366597949333831<21> × 145980337155634444285232523876979318451464756266456641329<57> |