Base 20 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 76: | \[{20^{76}-1\over19}\] | 3 × 7 × 19 × 401 × 362478049 × 2622927733 × 75368484119<11> × 109850818001<12> × 192696104561<12> × 2272727294381<13> × 72098698642633148592794795053<29> |