TheoremDB

Problem packetResearch packetR28

R28Computational evidence

The exact finite maximum for {0,1,2,4} is 62

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Authored summary

Every additive-square-free word over {0,1,2,4} has length at most 62. Exactly two length-62 words occur in the complete search tree, and they form one reversal orbit.

The record reports a computation within its stated scope.

Recorded status: supported

Recorded scope: all finite additive-square-free words over the exact integer alphabet {0,1,2,4}, including the empty word

Complete recorded scope and conditions
{
  "kind": "bounded",
  "statement": "all finite additive-square-free words over the exact integer alphabet {0,1,2,4}, including the empty word",
  "bounds": {
    "alphabet_size": {
      "min": 4,
      "max": 4
    },
    "alphabet_maximum": {
      "min": 4,
      "max": 4
    },
    "word_length": {
      "min": 0,
      "max": 62
    }
  },
  "exhaustive": true
}

Originating problem: Infinite additive-square avoidance over a finite integer alphabet

Authored record and scope
Authored title
The exact finite maximum for {0,1,2,4} is 62
Record type
claim
Stored status
supported
Evidence grade
computational
Recorded scope data
{ "kind": "bounded", "statement": "all finite additive-square-free words over the exact integer alphabet {0,1,2,4}, including the empty word", "bounds": { "alphabet_size": { "min": 4, "max": 4 }, "alphabet_maximum": { "min": 4, "max": 4 }, "word_length": { "min": 0, "max": 62 } }, "exhaustive": true }

2Authored explanation

After normalizing by translation and gcd and identifying reflections, {0,1,2,4} is the first primitive four-letter alphabet outside the balanced family when alphabets are ordered by maximum letter and then lexicographically. Two independent exact DFS implementations closed its full prefix tree. Each visited 19,097,778 nodes and 5,350,440 terminal leaves. The deepest level is 62 and contains two words. One is 02012404142012421014102010242102414240424120241210212402414204; the other is its reversal, 40241420421201214202142404241420124201020141012421024140421020. This result concerns one finite alphabet. It leaves the existence question over other finite alphabets open.

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Replay material: source only

3Evidence

Replay package: source only

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

Verification source: Independent exact Python and C++20 exhaustive searches executed on macOS arm64 on 2026-07-28

4What was measured

Execution

nodes19,097,778leaves5,350,440maximum length62maximizer count2reversal orbits1exact integer arithmeticyesrandomnessnone

5How it connects

Evidenced by

Tested by

Recorded for

Machine-readable record

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json
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  "ref": "R28",
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  "slug": "asq-claim-alphabet-0124-maximum-62",
  "type": "claim",
  "title": "The exact finite maximum for {0,1,2,4} is 62",
  "summary": "Every additive-square-free word over {0,1,2,4} has length at most 62. Exactly two length-62 words occur in the complete search tree, and they form one reversal orbit.",
  "relevance": "For Infinite additive-square avoidance over a finite integer alphabet, record asq-claim-alphabet-0124-maximum-62 (“The exact finite maximum for {0,1,2,4} is 62”) records a bound, answer, status fact, or structural consequence. The record states: Every additive-square-free word over {0,1,2,4} has length at most 62.",
  "relevance_source": "recorded",
  "body": "After normalizing by translation and gcd and identifying reflections, {0,1,2,4} is the first primitive four-letter alphabet outside the balanced family when alphabets are ordered by maximum letter and then lexicographically. Two independent exact DFS implementations closed its full prefix tree. Each visited 19,097,778 nodes and 5,350,440 terminal leaves. The deepest level is 62 and contains two words. One is 02012404142012421014102010242102414240424120241210212402414204; the other is its reversal, 40241420421201214202142404241420124201020141012421024140421020. This result concerns one finite alphabet. It leaves the existence question over other finite alphabets open.",
  "status": "supported",
  "evidence_grade": "computational",
  "scope": {
    "kind": "bounded",
    "statement": "all finite additive-square-free words over the exact integer alphabet {0,1,2,4}, including the empty word",
    "bounds": {
      "alphabet_size": {
        "min": 4,
        "max": 4
      },
      "alphabet_maximum": {
        "min": 4,
        "max": 4
      },
      "word_length": {
        "min": 0,
        "max": 62
      }
    },
    "exhaustive": true
  },
  "reproduction": {
    "schema": "theoremdb-reproduction-v1",
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    },
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  "formal_statement": null,
  "source": {
    "url": null,
    "locator": "Independent exact Python and C++20 exhaustive searches executed on macOS arm64 on 2026-07-28"
  },
  "models": [],
  "continuation": null,
  "relations": [
    {
      "slug": "R30",
      "title": "Any positive construction needs at least four letters",
      "object_type": "claim",
      "relation": "informs",
      "direction": "incoming"
    },
    {
      "slug": "R22",
      "title": "Reproduce the balanced-family table through maximum letter 8",
      "object_type": "attempt",
      "relation": "informs",
      "direction": "incoming"
    },
    {
      "slug": "R19",
      "title": "Exact additive-square-free prefix-tree enumerator",
      "object_type": "artifact",
      "relation": "evidences",
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    },
    {
      "slug": "R18",
      "title": "Independent C++ exact search for {0,1,2,4}",
      "object_type": "artifact",
      "relation": "tests",
      "direction": "incoming"
    },
    {
      "slug": "R24",
      "title": "Search for a low-expansion morphism and certify it",
      "object_type": "attempt",
      "relation": "informs",
      "direction": "outgoing"
    },
    {
      "slug": "additive-square-finite-alphabet",
      "title": "additive square finite alphabet",
      "object_type": "problem",
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  ]
}

7Provenance

View source, identifiers, and projection details

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

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