Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 293: | \[{21^{293}-1\over20}\] | 587 × 111341 × 86488327 × 5461601297539<13> × 19136334975601289<17> × 172325677562463355106666177813<30> × [1263117912134518013648073063343492765393589593430209839317399421109549644452972418364525598871226353757043939043600475599865356934008265487329914669839839336171570770061087916607622336670341261568115257274512011564520770045547146334837865835824680016372575980572630072093426489608754177910418163126788283896195779<313>] |