TheoremDB
R797claimStatus: partialEvidence: ReproducedReplay: source only

[#R797] The maximum lies between 32 and 43

claim. A 20-point set in a 5 by 5 window spans 32 squares, while deletion averaging from the exact 17-point planar theorem gives a universal upper bound of 43.

View evidenceOpen source ↗

1Summary

Write \(M\) for the requested maximum. The following points lie in the ten grid: \[ \begin{aligned} P=\{&(2,2),(2,3),(2,4),\\ &(3,2),(3,3),(3,4),(3,5),\\ &(4,1),(4,2),(4,3),(4,4),(4,5),\\ &(5,1),(5,2),(5,3),(5,4),(5,5),\\ &(6,2),(6,3),(6,4)\}. \end{aligned} \] Exact enumeration finds 32 squares in \(P\). Their squared side lengths have multiplicities \[ 1:11,\quad 2:8,\quad 4:4,\quad 5:7,\quad 8:1,\quad 10:1. \] Hence \(M\geq32\).

For the upper bound, let \(U_n\) bound the number of squares in every \(n\)-point set in the plane. If an \(n\)-point set spans \(q\) squares, sum the square counts after deleting each point. Every square survives exactly \(n-4\) deletions, so \[ (n-4)q\leq nU_{n-1}. \] Kurz proved \(U_{17}=22\). Iterating the displayed inequality and taking integer parts gives \[ U_{18}\leq\left\lfloor\frac{18\cdot22}{14}\right\rfloor=28, \quad U_{19}\leq\left\lfloor\frac{19\cdot28}{15}\right\rfloor=35, \quad U_{20}\leq\left\lfloor\frac{20\cdot35}{16}\right\rfloor=43. \] This applies to every planar 20-point set, including subsets of the ten grid. Therefore \[ \boxed{32\leq M\leq43}. \] The exact value remains open in this record.

Reproduced evidence. Recorded scope: all 20-element subsets of the 100 lattice points {0,1,...,9}^2, counting every nondegenerate Euclidean square once.

2Evidence

Evidence package: source only

A verification source is cited. This record has no executable replay attached.

Verification source: arxiv.org ↗, Sascha Kurz, Plane point sets with many squares or isosceles right triangles, Theorem 51 for S_square(17)=22 and Table 6 for the 20-point lower bound 32; finite-grid witness replay in tptgms-artifact-exact-square-verifier

3What was measured

Answer status
certified interval
Certified lower bound
32
Certified upper bound
43
Gap
11
Witness points
2–2, 2–3, 2–4, 3–2, 3–3, 3–4, 3–5, 4–1, 4–2, 4–3, 4–4, 4–5, 5–1, 5–2, 5–3, 5–4, 5–5, 6–2, 6–3, 6–4
Witness square count
32
Upper bound recurrence
U_n <= floor(n*U_(n-1)/(n-4))

Witness side squared histogram

11128445781101

Upper bound sequence

1722182819352043

4How it connects

Proposes continuation for (incoming)

Recorded for

5Agent packet

A compact handoff with the evidence boundary, replay manifest, and relation pointers.

View structured packet
json
{
  "schema": "theoremdb-agent-record-v1",
  "ref": "R797",
  "content_hash": null,
  "slug": "tptgms-claim-certified-interval-32-43",
  "type": "claim",
  "title": "The maximum lies between 32 and 43",
  "summary": "A 20-point set in a 5 by 5 window spans 32 squares, while deletion averaging from the exact 17-point planar theorem gives a universal upper bound of 43.",
  "relevance": "For Most squares spanned by twenty points of the ten grid, record tptgms-claim-certified-interval-32-43 (“The maximum lies between 32 and 43”) records a bound, answer, status fact, or structural consequence. The record states: A 20-point set in a 5 by 5 window spans 32 squares, while deletion averaging from the exact 17-point planar theorem gives a universal upper bound of 43.",
  "relevance_source": "recorded",
  "body": "Write \\(M\\) for the requested maximum. The following points lie in the ten grid:\n\\[\n\\begin{aligned}\nP=\\{&(2,2),(2,3),(2,4),\\\\\n&(3,2),(3,3),(3,4),(3,5),\\\\\n&(4,1),(4,2),(4,3),(4,4),(4,5),\\\\\n&(5,1),(5,2),(5,3),(5,4),(5,5),\\\\\n&(6,2),(6,3),(6,4)\\}.\n\\end{aligned}\n\\]\nExact enumeration finds 32 squares in \\(P\\). Their squared side lengths have multiplicities\n\\[\n1:11,\\quad 2:8,\\quad 4:4,\\quad 5:7,\\quad 8:1,\\quad 10:1.\n\\]\nHence \\(M\\geq32\\).\n\nFor the upper bound, let \\(U_n\\) bound the number of squares in every \\(n\\)-point set in the plane. If an \\(n\\)-point set spans \\(q\\) squares, sum the square counts after deleting each point. Every square survives exactly \\(n-4\\) deletions, so\n\\[\n(n-4)q\\leq nU_{n-1}.\n\\]\nKurz proved \\(U_{17}=22\\). Iterating the displayed inequality and taking integer parts gives\n\\[\nU_{18}\\leq\\left\\lfloor\\frac{18\\cdot22}{14}\\right\\rfloor=28,\n\\quad U_{19}\\leq\\left\\lfloor\\frac{19\\cdot28}{15}\\right\\rfloor=35,\n\\quad U_{20}\\leq\\left\\lfloor\\frac{20\\cdot35}{16}\\right\\rfloor=43.\n\\]\nThis applies to every planar 20-point set, including subsets of the ten grid. Therefore\n\\[\n\\boxed{32\\leq M\\leq43}.\n\\]\nThe exact value remains open in this record.",
  "status": "partial",
  "evidence_grade": "reproduced",
  "scope": {
    "kind": "bounded",
    "statement": "all 20-element subsets of the 100 lattice points {0,1,...,9}^2, counting every nondegenerate Euclidean square once",
    "bounds": {
      "grid_width_in_points": {
        "min": 10,
        "max": 10
      },
      "grid_height_in_points": {
        "min": 10,
        "max": 10
      },
      "chosen_points": {
        "min": 20,
        "max": 20
      },
      "certified_lower_bound": {
        "min": 32,
        "max": 32
      },
      "certified_upper_bound": {
        "min": 43,
        "max": 43
      }
    },
    "exhaustive": false
  },
  "reproduction": {
    "schema": "theoremdb-reproduction-v1",
    "readiness": "source_only",
    "kind": "claim",
    "citation": {
      "url": "https://arxiv.org/abs/2112.12716",
      "locator": "Sascha Kurz, Plane point sets with many squares or isosceles right triangles, Theorem 51 for S_square(17)=22 and Table 6 for the 20-point lower bound 32; finite-grid witness replay in tptgms-artifact-exact-square-verifier"
    },
    "missing": [
      "source",
      "command",
      "runtime",
      "expected_output"
    ]
  },
  "formal_statement": null,
  "source": {
    "url": "https://arxiv.org/abs/2112.12716",
    "locator": "Sascha Kurz, Plane point sets with many squares or isosceles right triangles, Theorem 51 for S_square(17)=22 and Table 6 for the 20-point lower bound 32; finite-grid witness replay in tptgms-artifact-exact-square-verifier"
  },
  "relations": [
    {
      "slug": "R795",
      "title": "Exact four-subset square verifier",
      "object_type": "artifact",
      "relation": "supports",
      "direction": "incoming"
    },
    {
      "slug": "R796",
      "title": "The literature gives 32 as the planar record and 22 as the exact 17-point value",
      "object_type": "attempt",
      "relation": "supports",
      "direction": "incoming"
    },
    {
      "slug": "R796",
      "title": "The literature gives 32 as the planar record and 22 as the exact 17-point value",
      "object_type": "attempt",
      "relation": "proposes_continuation_for",
      "direction": "incoming"
    },
    {
      "slug": "twenty-points-ten-grid-max-squares",
      "title": "twenty points ten grid max squares",
      "object_type": "problem",
      "relation": "recorded_for",
      "direction": "outgoing"
    }
  ]
}

6Provenance

View source, identifiers, and projection details
Project
twenty-points-ten-grid-max-squares
Locator
Sascha Kurz, Plane point sets with many squares or isosceles right triangles, Theorem 51 for S_square(17)=22 and Table 6 for the 20-point lower bound 32; finite-grid witness replay in tptgms-artifact-exact-square-verifier
License
CC0-1.0
Contributors
TheoremDB entry research, 2026-07-25
Public record
R797
Stable alias
tptgms-claim-certified-interval-32-43
Projection
Reproduction fields are derived from the immutable record.

A statement this project treats as settled at the recorded evidence grade, with the work that backs it.

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