Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 405: | \[2^{405}-1\] | 7 × 31 × 73 × 151 × 271 × 631 × 2593 × 23311 × 71119 × 262657 × 348031 × 537841 × 97685839 × 49971617830801<14> × 11096527935003481<17> × 17645665556213400107370602081155737281406841<44> |