Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 243: | \[{4^{243}-1\over3}\] | 35 × 7 × 19 × 73 × 163 × 487 × 1459 × 2593 × 71119 × 87211 × 135433 × 139483 × 262657 × 97685839 × 272010961 × 16753783618801<14> × 192971705688577<15> × 3712990163251158343<19> × 10429407431911334611<20> × 918125051602568899753<21> |