Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 475: | \[2^{475}-1\] | 31 × 191 × 601 × 1801 × 4751 × 524287 × 18020551 × 420778751 × 30327152671<11> × 1369738735713888876695951<25> × 113709467433878120743807151<27> × 170617159758027087771086981194610206694353113401<48> |