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Long paper

Running least common multiples: distinct values and multiplicities

Erdős #269 By July 2026; revised 5 October 2026 Authorship, AI use and citation

Summary. For the prime set {2,3,5}, a five-map argument proves irrationality of the sum over distinct running LCMs. Two-prime sums reduce to a transcendental Hecke–Mahler value. For the repeated three-prime sum, an equivalent residue criterion leaves an arithmetic condition open. Complete ordinary arguments for general distinct-running-LCM sums and prime-power subseries are retained as remarks awaiting formalisation.

This paper covers distinct-height irrationality, all-rank kernel structure and the repeated-sum tail criteria, preserving the multiplicity distinction and the remaining open residue-window obligation.

It does not establish the validity of claims tagged Lean, which belongs to the cited kernel-checked source, or a solution to Erdős #269, which remains open.

In this paper

The unresolved repeated-sum question

The distinct sum at {2,3,5} is settled by Theorem 1.1. The general and subseries arguments remain ordinary proofs pending formalisation (Remarks 5.1 and 5.10). The finite-state calculations of Remark 5.8 have their own scope; the {2,3,5,7} automaton collision limits that interval criterion only.

For R{2,3,5}, the missing ingredient is not just another normalisation or one sharper finite enclosure. The coefficients, recurrence, quadratic bounds and denominator-clearing formula are explicit. We must exclude eventual integral reduced tails for every possible denominator, or equivalently prove the residue inequalities beyond every prescribed onset. The fixed-start formula explains why an early success does not suffice; the strip identity explains why avoiding floor crossings does not supply the proposed cancellation.

The rank and uniform-norm results concern the kernel, not the arithmetic of its sum. Finite tests, countability, radix recoding and denominator support do not close the remaining argument. The settled two-prime case uses Fan’s earlier reduction to the cited Hecke–Mahler value theorem.

About this paper

Authorship and AI use. Will Cook built and directed the research infrastructure and maintains the public release. He reviewed claims when he could. AI agents did most of the research and drafting. Cook did not independently verify every claim.

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