Base 20 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 206: | \[{20^{206}-1\over19}\] | 3 × 7 × 619 × 10301 × 1023409 × 1074432643259<13> × 13949254290107<14> × 41006820590689355038289<23> × 466124620389646774905361<24> × 4115434523032449785948580135200269<34> × 1718036979119065226057525390766657389584957481707090013114792003<64> × 1950070948916965761846787847690605126973611643746068035040182756758421447344488707729<85> |