Base 20 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 213: | \[{20^{213}-1\over19}\] | 421 × 1279 × 761689 × 13821571 × 647826721 × 12384468799<11> × 201161092255316201234202042361<30> × 53479501200832544983059521873139421<35> × 85348118507329492968982117791209473948471<41> × 61777752739108975259079961779208763786873373427879250247440461<62> × 268567904675118264709817260332481313135362028460937733517342984722054629<72> |