Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 274: | \[{4^{274}-1\over3}\] | 5 × 1097 × 15619 × 189061 × 168434085820849<15> × 32127963626435681<17> × 105498212027592977<18> × 32032215596496435569<20> × 5439042183600204290159<22> × 206875670104957744917147613<27> × 921525707911840587390617330886362701<36> |