Base 20 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 247: | \[{20^{247}-1\over19}\] | 19 × 3121 × 142559 × 9690539 × 230065681 × 75368484119<11> × 192696104561<12> × 41413929827219<14> × 4460872019481639529<19> × [2353881643573928108692218085404341129602188240642302178666027363933466642862988707386141992611644179812236850482030031624714269850645050648986056763517155772398767188417524786145379392739157805921850642854085183569517102631668417765917232951<241>] |