AI-reported failure of strong normality for the Copeland–Erdős constant

The decimal Copeland–Erdős constant formed by concatenating the primes is not simply strongly normal in base 10, and therefore is not strongly normal in base 10.

Sources for this record

What was already known

Copeland and Erdős proved decimal normality. Belshaw and Borwein posed the stronger fluctuation question; Catt, Coons and Velich left prime concatenation unresolved under the law-of-the-iterated-logarithm definition.

AI involvement AI-led

VibeMathed records the submitter’s account that ChatGPT-6 Astra chose the question, developed the proof and wrote Lean. The unbylined primary paper does not independently allocate the human and AI work.

VibeMathed records the submitter’s account that ChatGPT-6 Astra chose the question, developed the proof and wrote the Lean formalization. The primary paper has no byline and does not independently document the division of mathematical work. The AI-led label rests on the submitter attribution, not on the absence of a human byline.

Importance Notable

Answers a named question about the fluctuation of digits in a classical normal constant.

Limitations

Lean proves the conclusion from an explicit Ingham1937Input short-interval prime-count asymptotic. Ingham’s established analytic theorem is not formalized. The result addresses base 10, not strong normality in unrelated bases; outside expert review remains limited.

Technical verification Partial

The public Actions run succeeded for the pinned Lean revision. Lean checks the exact digit and discrepancy deduction from an explicit `Ingham1937Input` hypothesis. Ingham’s classical short-interval theorem is cited but not formalized here; the unconditional claim therefore has a documented formal-check boundary. VibeMathed reports reading the short paper, but identifies no named human checker of the entire argument. AIProofWatch did not rerun the build.

Formal checking

The pinned public Actions run succeeded at this commit. The completed Lean theorem proves failure of simple and full base-10 strong normality from explicit Ingham1937Input; the external analytic theorem is not formalized.

Checker
Lean 4 kernel, as reported by the project
Scope
The decimal Copeland–Erdős constant is not simply strongly normal in base 10 and hence not strongly normal, assuming Ingham’s published short-interval asymptotic.
Basis
Reported by the linked checker
Evidence source

Checking a formal statement does not establish that it matches the original problem.

Human understanding Few

Few is the default when evidence for a higher level is insufficient. No named person is documented explaining the central argument. Editorial reading or a separate AI review does not establish human understanding. Few is the default from missing evidence, not a finding that people cannot explain it.

Correction and publication history

2026-10-18 · publication

Pinned primary claim, prior baseline, AI attribution and checking scope reviewed for local inclusion without notification.

Read this published revision