Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
443: | \[2^{443}-1\] | 887 × 207818990653657<15> × 123219439267346362049744425289349676468781136823956005602631224069302162695430546376768705960936201429580820215522273<117> |