Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
523: | \[2^{523}-1\] | 160188778313202118610543685368878688932828701136501444932217468039063<69> × 171417691861249198128317096534322116476165056718630345094896620367860006486977101859504089<90> |