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Let be infinite such that . For any let
where . Is it true that, for almost all , the sequence is uniformly distributed in ?
Let be infinite, tending to infinity, such that . For any let
where . Is it true that, for almost all , the sequence is uniformly distributed in ?
Source: erdosproblems.com/492
An accepted solution exists. The statement is false.
Disproved, in the site's label, which credits Schmidt's 1969
theorem with showing that the general conjecture is false; the label
describes the corrected Statement. Theorem 1 of Schmidt [Sc69] (Studia Sci.
Math. Hungar. 4 (1969), refereed; p. 137) constructs a strictly increasing
real sequence with and
such that the test function , equal to on the lower
halves of its intervals and elsewhere, satisfies
for almost every ,
whereas uniform distribution of the positions would force these averages to
tend to (an authored translation, below); with for it
answers the corrected Statement no. It is an accepted full claim on
Schmidt's page,
refereed and credited by the site's curator, so the standing derived in the
frontmatter is solved, disproved. The sparse case of Davenport and
Erdős [DaEr63] (Magyar Tud. Akad. Mat. Kutató Int. Közl. 8 (1963),
refereed; the Theorem and the deduction (9), p. 4) is an accepted partial
claim on
the
Davenport--Erdős page: for a real sequence with
, the multiples of almost every are uniformly
distributed relative to provided the number of is
for some fixed . Other positive cases, for real
sequences: uniform distribution for every when the gaps increase
to infinity with (LeVeque [LV53]), and for almost all
when the gaps decrease (Davenport and LeVeque [DaLe63]). The
community database, in its update of 31 August 2025, lists the problem as
disproved.
The site's wording restricts to the positive integers; the
problem the site and its sources mean concerns real sequences, and the two
have opposite answers. What Erdős printed: both of Erdős's statements of the
question, [Er61], item 31 of Part I, printed p. 238, and [Er64b], Part IV,
item 4, printed p. 62, begin "Let be an infinite sequence
tending to infinity satisfying " and never make the
integers, and the primary sources agree: LeVeque subdivides by
real points ([LV53], Section 1, p. 757), Davenport and Erdős
take positive reals with ([DaEr63], p. 3), Davenport and
LeVeque take real ([DaLe63], the Theorem, p. 315), and Schmidt
a strictly increasing sequence of reals ([Sc69], p. 137). How the site's
curator reads it: the label DISPROVED and the commentary, which credits
Davenport and Erdős with the case and says that "the
general conjecture is false, as shown by Schmidt [Sc69]", judge the
real-sequence question, since Schmidt's counterexample has gaps tending to
zero and says nothing about integer sequences, whose gaps are at least ,
and since the sparse case would be redundant for integer sequences, all of
which satisfy it; the problem's thread is empty, so the label and commentary
are the whole of the ruling. Erdős's print and the curator's reading agree,
and the integer restriction is the site's transcription alone. The answers
differ. Under the site's wording, an infinite set of positive integers has at
most members below , so it meets the sparseness hypothesis of the
Davenport--Erdős Theorem, at most terms below for some
fixed , with , and the deduction (9) that follows the
Theorem ([DaEr63], p. 4) gives uniform distribution of in
for almost all : the site's wording is true for every such
, already for , where is the fractional part. Under the
corrected Statement, Schmidt's Theorem 1 ([Sc69], p. 137) constructs a real
sequence with whose gaps tend to zero along which
is not uniformly distributed for almost every : the
answer is no, and the standing judges this Statement. The change replaces
" be infinite" by " be infinite,
tending to infinity,"; "tending to infinity" is Erdős's own phrase, automatic
for a set of integers but needed for reals, since the bounded sequence
has while is undefined once
. Results about the site's wording, credited here: the sparse
case of Davenport and Erdős (1963), which contains every set of integers by
the one-line check above and is the partial claim on the corrected Statement
on
the Davenport--Erdős page;
and the Lean theorem erdos_492 in Boris Alexeev's repository of Lean proofs,
added on 2026-08-20
(file),
written by the AI systems Codex and GPT-5.6 Sol, whose module docstring
records that the counting hypothesis is automatic for integers; it proves the
site's wording in full and a special case of the corrected Statement, so it is
a claimed partial claim on
Alexeev's page.
That docstring is the earliest statement found here that the site's integer
wording is true.