Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 266: | \[{21^{266}-1\over20}\] | 2 × 11 × 43 × 631 × 3319 × 4523 × 609673 × 81867661 × 12061389013<11> × 54921106624003<14> × 263478423344974307<18> × 987749814642143197<18> × 39188712102054729290763779<26> × 1027619231425962708522784338595411210117<40> × 1376329311400850864038635648055279091721982394672149875047<58> × 948175293266954869500463698756935713088089028515629708586399<60> × 63329476461782882569173744712807443377466798335943392324014170553080956816124248119<83> |