Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 403: | \[{21^{403}-1\over20}\] | 79 × 42719 × 189437 × 340939 × 516094151 × 2507557079 × 4540713283<10> × 51102693071<11> × 3936833990413<13> × 272581865551637989<18> × 30359455746216650070629466037<29> × 54516254994822645086530641499<29> × 30757032609763895138508251732200568369652963210041444469929608714910720772767827274622106246498322154992806782524013109162036248745189072469822550734889651672096144676432919911065418232640081776698038696784973757317115352304633312026546870150502120445993878752541702224324679821439240393641478971309549419344862055747380180181558024504815186870730279124525454474188454253285332033550190483<389> |