Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 501: | \[{4^{501}-1\over3}\] | 3 × 7 × 304609 × 2349023 × 223318747 × 1134974373913<13> × 25129004796912072003423103<26> × 79638304766856507377778616296087448490695649<44> × 62357403192785191176690552862561408838653121833643<50> × 151092646351275754169926860141067686815825706612457363611594727781012756281<75> × 198950585925702911694795949136325395391616590334589163147577781735447402953<75> |