Base 4 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 381: | \[{4^{381}-1\over3}\] | 3 × 7 × 2287 × 3049 × 15241 × 349759 × 38257184231365987<17> × 56713727820156410577229101238628035243<38> × 170141183460469231731687303715884105727<39> × 82723179283707558079607521798312521771184766697594996913<56> × 339212878596211796110770323541353281494127285320354524672773903<63> |