Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 341: | \[{21^{341}-1\over20}\] | 2729 × 4540713283<10> × 3936833990413<13> × 17513875027111<14> × 272581865551637989<18> × [1616573984542892692472890083612940427075128027034350008409540798105103659588775545213602062866214597398795915295517299749394774892285266450180625095418140036160304865444519822813217125217257077478989366331373236790592333162739778187206990747499226507248827229164642245560794210391307496612118683142768251098151022816778292172528473538603743636054960445506488351741940281690076589054321687034369<394>] |