Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 455: | \[{21^{455}-1\over20}\] | 5 × 43 × 79 × 131 × 631 × 1471 × 3319 × 16381 × 40841 × 189437 × 443431 × 4149601 × 20028751 × 516094151 × 421503321597121<15> × 35381269315942497678572657090020747<35> × 47999819885150422820855221255204479443163906801765079421<56> × 4264091474110761334946377629947327910839217826620223120485043<61> × [40365065871266816200931080556933118385129479676168567644415942984042230362142373988477112316580669038554862016960596934899369152572192944862954303736875886519750552775307209510399744197762278261419240443473610302960678739356105904675446033415021174011908693297682085236083320817996925633331742635016199883353850521798700496942779956957018016785683692758487312002187561665908501<377>] |