Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.
Updated
Claim. The integers and are consecutive powerful numbers and neither is a square, since . So the first question of Problem 365, read as the site reads it (must one of , be a square?), has answer no. The observation is in S. W. Golomb, Powerful numbers, Amer. Math. Monthly 77 (1970), no. 8, 848--852 (the site's reference list prints 848--855). Golomb splits consecutive powerful pairs into those with a square member and those without, the division Walker later described completely.
Covers. The first question only (the part pell): one counterexample
refutes it. The second question, whether the number of such is
, is untouched.
Depends on. Nothing in this wiki; the claim is a finite check recorded in the cited paper.
Acceptance. Refereed: the paper appeared in the American Mathematical
Monthly, a refereed journal, in October 1970, the month this page is dated
to. The site's commentary records the answer no and credits Golomb, but the
site labels the problem OPEN (page last edited 31 October 2025), so that
commentary is not acceptance of the problem and the page lists no reviewed
evidence. Formalization: Collin Yuanjie Ren's Lean package JSP-000301,
pinned above at the commit of 2026-09-16, proves
consecutive_powerful_not_always_square, that not every pair of consecutive
powerful positive integers has a square member, through the explicit witness
, ; its README credits the counterexample to Golomb, says the
contribution sought is formalization rather than a new result, and says the
code was prepared with OpenAI Codex assistance, with the axioms propext,
Classical.choice and Quot.sound. The corpus has not built or audited
it, so no formalized evidence is listed. The arithmetic of the
counterexample is checked above; nothing else is reviewed here.