Counting Langford pairings for 31 and 32 pairs
Compute the exact number of Langford pairings of order 31 and 32, estimated near 5×10^24 and 9×10^25; counts are known up to order 28.
| 1 | { |
| 2 | "domain": "computer-science", |
| 3 | "topics": [ |
| 4 | "constraint-programming", |
| 5 | "algorithms-complexity" |
| 6 | ], |
| 7 | "type": "algorithm", |
| 8 | "source": { |
| 9 | "key": "csplib", |
| 10 | "name": "CSPLib", |
| 11 | "url": "https://www.csplib.org/Problems/prob024/", |
| 12 | "id": "prob024", |
| 13 | "curator": "CSPLib editors", |
| 14 | "poser": "Toby Walsh", |
| 15 | "status": "open", |
| 16 | "as_of": "2026-10-20", |
| 17 | "catalog": "0521c19bbd38" |
| 18 | }, |
| 19 | "review": true, |
| 20 | "approval": "first-time" |
| 21 | } |