Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
293: | \[{4^{293}-1\over3}\] | 587 × 26371 × 33403 × 40122362455616221971122353<26> × 13453890779540632945331892129844577<35> × 762551893101410166019390283047520363896913<42> × 396645227028138890415611220710757921643910743103031701971222447<63> |