Research notes on every problem, and a library of the papers behind them. Built from the open erdos repository.
Updated
Claim. Let be the number of distinct values of Euler's function in . The last clause of Theorem 2.1 of OpenAI, An asymptotic formula for the number of totients, OpenAI Math Release preprint, 25 September 2026 (the preprint link, at the pinned revision of the release repository; the manuscript's author line is "OpenAI", and the release README says the manuscripts were produced by an internal OpenAI model and stand at different stages of verification, not all with Lean formalizations), states that for every fixed real
At this is the first question of Problem 416, answered yes; the theorem covers every positive scale, which is the regular-variation question Erdős and Hall posed beside the problem and Erdős repeated in 1979. The manuscript is carded at its intake card, whose Theorem 2.1 page transcribes the statement. The same theorem's other clauses, an asymptotic equivalent with an explicitly constructed coefficient, are the subject of the separate pending full claim on the second question; this page records only the fixed-scale limit. The proof orders the prime factors of a typical preimage from the largest down, counts a long prefix of them by the volume of a simplex that Ford's normal-structure theorems describe, retains a short arithmetic tail exactly, and controls collisions between prefixes by Maier and Pomerance's layered shifted-prime method in Ford's form; the fixed-scale limit comes from comparing one representation count at the two endpoints and with common parameters, before the arithmetic limit is identified.
Covers. First question only: for every fixed , so . The second question stays claimed: whether the manuscript's equivalent is a formula in elementary functions is unsettled, and that claim has its own pending page.
Formalization. The release's Lean tree (folder lean/ at the pinned
revision, with the release's pinned Lean and Mathlib) proves
OAI.TotientAsymptotic.totient_asymptotic_formula in
OAI/NumberTheory/TotientAsymptotic/UnconditionalMain.lean, a conjunction
whose fourth conjunct is
∀ c : ℝ, 0 < c → Tendsto (fun x => V (c*x)/V x) atTop (nhds c)with, in the comparator challenge
ComparatorChallenges/TotientAsymptotic.lean,
def IsTotient (v : ℕ) : Prop := ∃ n : ℕ, 0 < n ∧ n.totient = v
def V (x : ℝ) : ℝ := by
classical
exact (((Finset.Icc 1 ⌊x⌋₊).filter IsTotient).card : ℝ)The challenge's configuration TotientAsymptotic.json pins the declaration,
with the three companion theorems of the family, permits only the axioms
propext, Quot.sound and Classical.choice, and lists no definitions;
the release's family note lean/docs/024.md names it as the comparator for
the totient-count asymptotics and regular variation. The declaration has no
hypotheses, and its is the site's count clause for clause: values
with , each counted once, and the condition
on the preimage excluding only the value . Real
implies the integer version, and for large keeps the quotient
meaningful. The external imports are three modules of
PrimeNumberTheoremAnd at a pinned commit, patched in the release to remove
two unused sorried lemmas.
Depends on. Nothing in this wiki: the proof is self-contained in the manuscript and its Lean tree.
Acceptance. Formalized: this corpus's verification built the solution module
and the comparator challenge from the release at the pinned revision, printed
the axioms of totient_asymptotic_formula, which were exactly propext,
Classical.choice and Quot.sound, and found the comparator fingerprint of the
pinned challenge statement identical to the solution's; the result was recorded
on 2026-10-07. The statement audit that formalized requires is this corpus's
own, of 2026-10-07: it unfolded IsTotient and V, compared the fourth
conjunct with the problem page's Statement (the counting function, the scale
, the direction of the limit, the quantifier over real ) and judged that
it answers the first question yes, with every as a stronger range. Not
reviewed: no outside reviewer, referee or acceptance by the site is recorded;
the site labels the problem OPEN and its proof-claims thread does not list the
release. Not refereed: the manuscript is an unrefereed release preprint with no
arXiv version, attributed by the release to an internal model. An earlier
independent formal proof of the case is the
Conjectures.io record,
by a different method.