A composite number that passes the Baillie–PSW test
Find an odd composite number passing both the strong base-2 Fermat test and the strong Lucas test of Baillie–PSW; none is known below 2^64.
| 1 | { |
| 2 | "domain": "mathematics", |
| 3 | "topics": [ |
| 4 | "number-theory", |
| 5 | "algorithms-complexity" |
| 6 | ], |
| 7 | "type": "construction", |
| 8 | "also": [ |
| 9 | "proof" |
| 10 | ], |
| 11 | "source": { |
| 12 | "key": "frontiermath-open", |
| 13 | "name": "FrontierMath: Open Problems", |
| 14 | "url": "https://epoch.ai/frontiermath/open-problems/baillie-psw", |
| 15 | "id": "baillie-psw", |
| 16 | "curator": "Epoch AI", |
| 17 | "status": "unsolved", |
| 18 | "as_of": "2026-10-20", |
| 19 | "catalog": "0521c19bbd38" |
| 20 | } |
| 21 | } |