Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 427: | \[{21^{427}-1\over20}\] | 43 × 631 × 3319 × 15373 × 12519763 × 13675957 × 1128331159687<13> × 9842498182599097<16> × 1814065850324073713<19> × 46598687502593879081017<23> × 57398774322642953389748085156004642469<38> × [15146770702780303126743396463617574984685556371775614288128503934267390047906194803230577139054595678873014111251772284551980037681499966400760369499601394409820249798485690510671813222836311655197968248371764615656746459362843231144556156936175045656870598601118047001931032461074787287217415752136327981108125149639394162291580912303504520642987958496379497527266405177663138874466741359366069124349231480738148334395351984216157<431>] |