Problem packetResearch packetR716
The exact maximum is M(50)=8
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The record reports a computation within its stated scope.
Recorded status: established
Recorded scope: all subsets of {1,...,50} whose off-diagonal sums and positive differences form one collision-free collection
Complete recorded scope and conditions
{
"kind": "bounded",
"statement": "all subsets of {1,...,50} whose off-diagonal sums and positive differences form one collision-free collection",
"bounds": {
"ambient_maximum": {
"min": 50,
"max": 50
},
"set_size": {
"min": 8,
"max": 10
}
},
"exhaustive": true
}Originating problem: Largest jointly sum-and-difference-distinct subset of {1,...,50}
Authored record and scope
- Authored title
- The exact maximum is M(50)=8
- Record type
- claim
- Stored status
- established
- Evidence grade
- computational
- Recorded scope data
- { "kind": "bounded", "statement": "all subsets of {1,...,50} whose off-diagonal sums and positive differences form one collision-free collection", "bounds": { "ambient_maximum": { "min": 50, "max": 50 }, "set_size": { "min": 8, "max": 10 } }, "exhaustive": true }
2Authored explanation
For a \(k\)-element set, the combined collection has \(2\binom{k}{2}=k(k-1)\) entries. Every positive difference and every sum lies in \(\{1,\ldots,99\}\), so \(k(k-1)\leq99\) and \(k\leq10\).
The set \[ S=\{8,18,22,23,30,41,47,50\} \] produces 56 distinct combined values, with minimum 1 and maximum 97. This proves \(M(50)\geq8\).
The executable certificate enumerates every increasing nine-tuple in \(\{1,\ldots,50\}\). It carries a bit mask for all sums and differences created by the current partial set. An extension is retained exactly when its new values avoid the mask and one another. The search reaches no depth-nine leaf. The property passes to subsets, so every valid set of size at least nine would contain a valid nine-element subset. Hence \(M(50)\leq8\), and the two bounds give \[ M(50)=8. \]
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Replay material: source only
3Evidence
A verification source is cited. This record has no executable replay attached.
Verification source: doi.org ↗, Independent exhaustive certificate sdd50-artifact-exhaustive-nine, executed on 2026-07-24
4What was measured
5How it connects
Evidenced by
- artifact
Informed by
- claim
Recorded for
- problem
Cite this record
Cite the original sources separately.
Machine-readable record
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"slug": "sdd50-claim-exact-value",
"type": "claim",
"title": "The exact maximum is M(50)=8",
"summary": "The set {8,18,22,23,30,41,47,50} attains eight, and a complete search finds no valid nine-element subset.",
"relevance": "This records a result, observation, or conjecture used to assess the target problem.",
"relevance_source": "derived",
"body": "For a \\(k\\)-element set, the combined collection has \\(2\\binom{k}{2}=k(k-1)\\) entries. Every positive difference and every sum lies in \\(\\{1,\\ldots,99\\}\\), so \\(k(k-1)\\leq99\\) and \\(k\\leq10\\).\n\nThe set\n\\[\nS=\\{8,18,22,23,30,41,47,50\\}\n\\]\nproduces 56 distinct combined values, with minimum 1 and maximum 97. This proves \\(M(50)\\geq8\\).\n\nThe executable certificate enumerates every increasing nine-tuple in \\(\\{1,\\ldots,50\\}\\). It carries a bit mask for all sums and differences created by the current partial set. An extension is retained exactly when its new values avoid the mask and one another. The search reaches no depth-nine leaf. The property passes to subsets, so every valid set of size at least nine would contain a valid nine-element subset. Hence \\(M(50)\\leq8\\), and the two bounds give\n\\[\nM(50)=8.\n\\]",
"status": "established",
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"schema": "theoremdb-reproduction-v1",
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"kind": "claim",
"citation": {
"url": "https://doi.org/10.1109/TCOM.1986.1096587",
"locator": "Independent exhaustive certificate sdd50-artifact-exhaustive-nine, executed on 2026-07-24"
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"locator": "Independent exhaustive certificate sdd50-artifact-exhaustive-nine, executed on 2026-07-24"
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"title": "Exhaustive nine-element branch certificate",
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{
"slug": "R717",
"title": "The condition strengthens the Golomb ruler and Sidon property",
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}7Provenance
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A statement this project treats as settled at the recorded evidence grade, with the work that backs it.