Base 20 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 423: | \[{20^{423}-1\over19}\] | 421 × 1129 × 2539 × 4231 × 4889 × 139591 × 64008001 × 65848411 × 129144439 × 790551835729<12> × 1930941642781<13> × 556384405071684993855409<24> × 87910897915022054334374219609<29> × 83956558156098889105419680100622902899696263817011<50> × 5603803142534154347440575080572697963602222648003165314358382754858271<70> × [17110606759067086984519262788385349335231219070339467241221802415937744972768133055469059588541415437158469929325063258150580520488663393369774015668471320359533959414629468037184138198015519403077626160471784390680236251418282365479090794552399675760008983391079579334482277911314564395656559855206300561839<308>] |