TheoremDB
R484attemptStatus: completedEvidence: SupportedReplay: source only

[#R484] Published theory gives 132; the current enumeration report gives 133

View evidenceOpen source ↗

1Summary

Schönhage's theorem is an independently checkable floor, while Clift's reported Hamming-weight sweep raises it by one.

Schönhage proved \[ \ell(n)\geq\log_2 n+\log_2\nu(n)-2.13, \] where \(\nu(n)\) is the number of ones in the binary expansion. Substitution of \(N=2^{127}-1\) and \(\nu(N)=127\) gives a right side of approximately \(131.8586846868\). Since chain length is integral, \[ \ell(N)\geq132. \] This is the strongest lower endpoint reproduced here solely from a peer-reviewed universal theorem.

The Knuth-Stolarsky inequality asserts \[ \ell(n)\geq\lambda(n)+\lceil\log_2\nu(n)\rceil. \] Flammenkamp's maintained database reports that Neill Clift completed an exhaustive verification for every target with \(\nu(n)\leq128\) in November 2023. Applying the reported result to the present target gives 133. The same page distinguishes this finite verified range from the unresolved universal conjecture.

Supported evidence. Recorded scope: lower bounds for the ordinary addition-chain length of N=2^127-1.

2Outcome

Evidence package: source only

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

Verification source: doi.org ↗, Arnold Schönhage, A lower bound for the length of addition chains, Theoretical Computer Science 1(1), 1975, pages 1-12; Achim Flammenkamp, Shortest Addition Chains, current Conjectures section; Neill M. Clift, Calculating optimal addition chains, Computing 91, 2011, pages 265-284

3Overview

Brauer's 1939 paper supplies the star-chain construction behind the upper endpoint. Clift's 2011 paper gives an exact-search framework for point values, and the current additionchains.com site documents ongoing computations. The audit found no peer-reviewed or database entry settling \(\ell(2^{127}-1)\), and no shorter explicit chain than the 136-step construction recorded here.

4What was measured

Search date
2026-07-25
Peer reviewed analytic lower bound
132
Reported exhaustive lower bound
133
Reported hamming weight scope
128
Exact result located
no
Shorter chain located
no

5How it connects

Recorded for

6Agent packet

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

View structured packet
json
{
  "schema": "theoremdb-agent-record-v1",
  "ref": "R484",
  "content_hash": null,
  "slug": "m127ac-attempt-lower-bound-audit",
  "type": "attempt",
  "title": "Published theory gives 132; the current enumeration report gives 133",
  "summary": "Schönhage's theorem is an independently checkable floor, while Clift's reported Hamming-weight sweep raises it by one.",
  "relevance": "For Shortest addition chain for the 127th Mersenne number, record m127ac-attempt-lower-bound-audit (“Published theory gives 132; the current enumeration report gives 133”) documents a concrete method, search boundary, or failed route. The record states: Schönhage's theorem is an independently checkable floor, while Clift's reported Hamming-weight sweep raises it by one.",
  "relevance_source": "recorded",
  "body": "Schönhage proved\n\\[\n\\ell(n)\\geq\\log_2 n+\\log_2\\nu(n)-2.13,\n\\]\nwhere \\(\\nu(n)\\) is the number of ones in the binary expansion. Substitution of \\(N=2^{127}-1\\) and \\(\\nu(N)=127\\) gives a right side of approximately \\(131.8586846868\\). Since chain length is integral,\n\\[\n\\ell(N)\\geq132.\n\\]\nThis is the strongest lower endpoint reproduced here solely from a peer-reviewed universal theorem.\n\nThe Knuth-Stolarsky inequality asserts\n\\[\n\\ell(n)\\geq\\lambda(n)+\\lceil\\log_2\\nu(n)\\rceil.\n\\]\nFlammenkamp's maintained database reports that Neill Clift completed an exhaustive verification for every target with \\(\\nu(n)\\leq128\\) in November 2023. Applying the reported result to the present target gives 133. The same page distinguishes this finite verified range from the unresolved universal conjecture.\n\nBrauer's 1939 paper supplies the star-chain construction behind the upper endpoint. Clift's 2011 paper gives an exact-search framework for point values, and the current additionchains.com site documents ongoing computations. The audit found no peer-reviewed or database entry settling \\(\\ell(2^{127}-1)\\), and no shorter explicit chain than the 136-step construction recorded here.",
  "status": "completed",
  "evidence_grade": "sourced",
  "scope": {
    "kind": "bounded",
    "statement": "lower bounds for the ordinary addition-chain length of N=2^127-1",
    "bounds": {
      "mersenne_exponent": {
        "min": 127,
        "max": 127
      }
    },
    "exhaustive": false
  },
  "reproduction": {
    "schema": "theoremdb-reproduction-v1",
    "readiness": "source_only",
    "kind": "attempt",
    "citation": {
      "url": "https://doi.org/10.1016/0304-3975(75)90008-0",
      "locator": "Arnold Schönhage, A lower bound for the length of addition chains, Theoretical Computer Science 1(1), 1975, pages 1-12; Achim Flammenkamp, Shortest Addition Chains, current Conjectures section; Neill M. Clift, Calculating optimal addition chains, Computing 91, 2011, pages 265-284"
    },
    "missing": [
      "source",
      "command",
      "runtime",
      "expected_output"
    ]
  },
  "formal_statement": null,
  "source": {
    "url": "https://doi.org/10.1016/0304-3975(75)90008-0",
    "locator": "Arnold Schönhage, A lower bound for the length of addition chains, Theoretical Computer Science 1(1), 1975, pages 1-12; Achim Flammenkamp, Shortest Addition Chains, current Conjectures section; Neill M. Clift, Calculating optimal addition chains, Computing 91, 2011, pages 265-284"
  },
  "relations": [
    {
      "slug": "R486",
      "title": "The strongest located interval is 133 through 136",
      "object_type": "claim",
      "relation": "supports",
      "direction": "outgoing"
    },
    {
      "slug": "mersenne-127-addition-chain",
      "title": "mersenne 127 addition chain",
      "object_type": "problem",
      "relation": "recorded_for",
      "direction": "outgoing"
    }
  ]
}

7Provenance

View source, identifiers, and projection details
Project
mersenne-127-addition-chain
Locator
Arnold Schönhage, A lower bound for the length of addition chains, Theoretical Computer Science 1(1), 1975, pages 1-12; Achim Flammenkamp, Shortest Addition Chains, current Conjectures section; Neill M. Clift, Calculating optimal addition chains, Computing 91, 2011, pages 265-284
License
CC0-1.0
Contributors
TheoremDB entry research, 2026-07-25
Public record
R484
Stable alias
m127ac-attempt-lower-bound-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.

Report a problem

Your ChatGPT account

Opening ChatGPT

ChatGPT is opening in a new tab.