Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 781: | \[{4^{781}-1\over3}\] | 23 × 89 × 683 × 228479 × 48544121 × 56409643 × 212885833 × 6511616671913<13> × 13952598148481<14> × 66232837958133438967<20> × 79034734517219615663<20> × 370549646190282993458807249710605687589893787382049438311221836912017<69> × 208330322620970625559449619171017280681294575846766796187666540066563147519451746148400079<90> × 7886353093975892344674220233909869188747040026972855989426616696804621307532561503024600149232545470825232486562259903355949774974892210874122143260159694766648495259916411671545519489126688710252487466339526659<211> |