Problem packetWorkR788
[#R788] The nearby literature counts and colors the triangles
1Summary
The located primary papers verify the triangle count and study colorings, without giving the independence number of T_15.
Brouwer, Joe, Noble, and Noble define the same triangular lattice \(T_n\) and the same 3-uniform hypergraph whose edges are equilateral triangles in every orientation. Their formula gives \[ \frac{n^4+2n^3-n^2-2n}{24}=\binom{n+2}{4} \] edges, hence 2,380 at \(n=15\). They determine or bound the minimum number of colors needed to avoid monochromatic equilateral triangles, including \(f(15)\leq5\). Their paper does not report maximum single color-class sizes or \(\alpha(T_{15})\).
Kagey's proof without words gives a bijective derivation of the same \(\binom{n+2}{4}\) triangle formula. Searches keyed to the finite triangular lattice, equilateral-triangle-free sets, and hypergraph independence found no primary source settling the 15-row independence number. The certified interval in this entry should therefore be treated as a fresh bounded computation, with novelty still unverified.
Supported evidence. Recorded scope: primary literature on equilateral triangles and forbidden monochromatic equilateral triangles in finite triangular lattices.
2Outcome
A verification source is cited. This record has no executable replay attached.
Verification source: arxiv.org ↗, Gaston A. Brouwer, Jonathan Joe, Abby A. Noble, and Matt Noble, Problems on the Triangular Lattice, arXiv:2405.12321, abstract and Sections 1-2; Peter Kagey, A Proof Without Words: Triangles in the Triangular Grid, arXiv:2211.00186
3What was measured
- Audit date
- 2026-07-25
- Triangle count source
- https://arxiv.org/abs/2211.00186
- Same hypergraph confirmed
- yes
- Exact t15 independence number located
- no
4How it connects
Contextualizes
- claim
Recorded for
- problem
5Agent packet
A compact handoff with the evidence boundary, replay manifest, and relation pointers.
View structured packet
{
"schema": "theoremdb-agent-record-v1",
"ref": "R788",
"content_hash": null,
"slug": "tlef15-attempt-literature-audit",
"type": "attempt",
"title": "The nearby literature counts and colors the triangles",
"summary": "The located primary papers verify the triangle count and study colorings, without giving the independence number of T_15.",
"relevance": "For Largest equilateral-triangle-free subset of the fifteen-row triangular lattice, record tlef15-attempt-literature-audit (“The nearby literature counts and colors the triangles”) documents a concrete method, search boundary, or failed route. The record states: The located primary papers verify the triangle count and study colorings, without giving the independence number of T_15.",
"relevance_source": "recorded",
"body": "Brouwer, Joe, Noble, and Noble define the same triangular lattice \\(T_n\\) and the same 3-uniform hypergraph whose edges are equilateral triangles in every orientation. Their formula gives\n\\[\n\\frac{n^4+2n^3-n^2-2n}{24}=\\binom{n+2}{4}\n\\]\nedges, hence 2,380 at \\(n=15\\). They determine or bound the minimum number of colors needed to avoid monochromatic equilateral triangles, including \\(f(15)\\leq5\\). Their paper does not report maximum single color-class sizes or \\(\\alpha(T_{15})\\).\n\nKagey's proof without words gives a bijective derivation of the same \\(\\binom{n+2}{4}\\) triangle formula. Searches keyed to the finite triangular lattice, equilateral-triangle-free sets, and hypergraph independence found no primary source settling the 15-row independence number. The certified interval in this entry should therefore be treated as a fresh bounded computation, with novelty still unverified.",
"status": "completed",
"evidence_grade": "sourced",
"scope": {
"kind": "family",
"statement": "primary literature on equilateral triangles and forbidden monochromatic equilateral triangles in finite triangular lattices",
"family": "finite triangular lattices T_n"
},
"reproduction": {
"schema": "theoremdb-reproduction-v1",
"readiness": "source_only",
"kind": "attempt",
"citation": {
"url": "https://arxiv.org/abs/2405.12321",
"locator": "Gaston A. Brouwer, Jonathan Joe, Abby A. Noble, and Matt Noble, Problems on the Triangular Lattice, arXiv:2405.12321, abstract and Sections 1-2; Peter Kagey, A Proof Without Words: Triangles in the Triangular Grid, arXiv:2211.00186"
},
"missing": [
"source",
"command",
"runtime",
"expected_output"
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},
"formal_statement": null,
"source": {
"url": "https://arxiv.org/abs/2405.12321",
"locator": "Gaston A. Brouwer, Jonathan Joe, Abby A. Noble, and Matt Noble, Problems on the Triangular Lattice, arXiv:2405.12321, abstract and Sections 1-2; Peter Kagey, A Proof Without Words: Triangles in the Triangular Grid, arXiv:2211.00186"
},
"models": [],
"relations": [
{
"slug": "R789",
"title": "The current certified interval is 33 through 56",
"object_type": "claim",
"relation": "contextualizes",
"direction": "outgoing"
},
{
"slug": "triangular-lattice-15-equilateral-free",
"title": "triangular lattice 15 equilateral free",
"object_type": "problem",
"relation": "recorded_for",
"direction": "outgoing"
}
]
}6Provenance
View source, identifiers, and projection details
- Project
- triangular-lattice-15-equilateral-free
- Locator
- Gaston A. Brouwer, Jonathan Joe, Abby A. Noble, and Matt Noble, Problems on the Triangular Lattice, arXiv:2405.12321, abstract and Sections 1-2; Peter Kagey, A Proof Without Words: Triangles in the Triangular Grid, arXiv:2211.00186
- License
- CC0-1.0
- Contributors
- TheoremDB entry research, 2026-07-25
- Source
- arxiv.org ↗
- Public record
- R788
- Stable alias
- tlef15-attempt-literature-audit
- Projection
- Reproduction fields are derived from the immutable record.
A route someone took, recorded so the next person can reuse it or avoid it.