Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 308: | \[{21^{308}-1\over20}\] | 22 × 112 × 13 × 17 × 23 × 29 × 43 × 89 × 631 × 661 × 3319 × 3697 × 6073 × 10362529 × 81867661 × 6225803431<10> × 68454248717<11> × 123679698913<12> × 17513875027111<14> × 4718573764413203147069<22> × 15502260840362954719909<23> × 37681894326794146626121<23> × 312273321889143336074893<24> × 39824892937303186001525100993399811<35> × 82721492925050166710438512180782661<35> × 4557276101739669313157253946749298236623032242013669493<55> × 101998481654795665862705057250680715901314310047761671255725181906787132803729185945655368785342471275757<105> |