Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.
Updated
The claim: infinitely many have no representation with
, so the first question of
Problem 205 has a negative
answer; the negative answer to the first is one to the second, whose bound
is no larger when . It is one to the third
because of how the counterexamples are built. For , is a multiple of
and of , with modulo a product of distinct primes at
least for each . So every is positive and divisible by
or by those primes, hence at least . For any with
, once is large, for all
these . The site's commentary (last edited 2026-04-05) credits the disproof
to Barreto and Leeham, working with ChatGPT and Aristotle, and its thanks line
names Kevin Barreto and Leeham among the contributors; Leeham is the forum
account of Liam Price, whose posts display under that name, and who posted the
formalization and the write-up. The community database dates the problem's
change to disproved on 2026-01-10. In the site's discussion thread on
2026-01-11, Price posted the Aristotle formalization of the construction as a
live Lean session (the formalization link above), then a write-up on Overleaf
(the preprint link above), which Price describes as ChatGPT's output, and
named Kevin Barreto as the collaborator with whom Price had worked on the site's
problems 728 and 729 by the same method: asking ChatGPT 5.2 to research the
problem and brainstorm, then an offline run of GPT-5.2 Thinking (the same day
Price wrote that the model was GPT-5.2 Thinking rather than GPT-5.2 Pro and
asked for the note on the community database's GitHub page to be changed) that
was not told the problem was open, with Aristotle formalizing the result. The
community database's AI-contributions wiki lists the result under Aristotle and
GPT-5.2 Thinking as a full solution in Lean. The headers of the later community
Lean files say that Wouter van Doorn suggested the approach, ChatGPT made it
into a complete informal proof and Aristotle formalized it. The quantified
strengthening posted the same day by Tao and Alexeev has its own page,
Tao–Alexeev 2026,
and is the form the later community Lean files prove; the session linked above
proves the form itself, from Mathlib alone.
Depends on. Nothing in this wiki.
Acceptance. Reviewed: the site's curator, Thomas F. Bloom, labels the
problem DISPROVED (LEAN) and credits the negative answer to Barreto and
Leeham in the problem's commentary (last edited 2026-04-05), and Terence
Tao, in the thread on 2026-01-11, described the construction, found it
surprisingly simple and listed it as a full solution under Section 1,
primary contributions, of the AI-contributions wiki of the community
database Tao maintains. The same day Nat Sothanaphan posted a human-readable
version of the quantified Lean proof and wrote that they had checked
everything by hand; that write-up is linked from the Tao–Alexeev page. No
refereed publication exists: the Overleaf write-up is ChatGPT's output and
unrefereed, and no library card digests it. The Lean session linked above
is a community file that this corpus has not built or audited, so no
formalized evidence is listed and the evidence is reviewed alone. The
Lean suffix of the site's label is a catalog label; what the linked formal
files prove is recorded on the problem page and on the Tao–Alexeev page.