Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 81: | \[{4^{81}-1\over3}\] | 34 × 7 × 19 × 73 × 163 × 2593 × 71119 × 87211 × 135433 × 262657 × 97685839 × 272010961 |
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 81: | \[{4^{81}-1\over3}\] | 34 × 7 × 19 × 73 × 163 × 2593 × 71119 × 87211 × 135433 × 262657 × 97685839 × 272010961 |