Erdős Problem a Daythe open tracker

Erdős Problem #5

OPENdatabase updated 2025-08-31

No proof or disproof is known, and it isn't known whether a finite computation could settle it.

What the community database records, not our verdict. erdosproblems.com no longer shows statuses (why).

The normalised prime gap \(\frac{p_{n+1}-p_n}{\log n}\), where \(p_n\) denotes the \(n\)-th prime.

The set \(S\) of limit points of \(\frac{p_{n+1}-p_n}{\log n}\). Only the *finite* limit points are collected here; that \(\infty\) is also a limit point is Westzynthius' theorem, recorded separately as `erdos_5.variants.westzynthius`. Erdős' question, as well as [HiMa88] and [Pi16], normalises the prime gaps by \(\log n\), whereas [GPY09], [BFM16] and [Me20] normalise by \(\log p_n\). Since \(\log p_n/\log n \to 1\) the two normalisations have the same limit points, so all the results below are stated for

Let \(C\geq 0\). Is there an infinite sequence of \(n_i\) such that \[\lim_{i\to \infty}\frac{p_{n_i+1}-p_{n_i}}{\log n_i}=C?\] We formalise "an infinite sequence of \(n_i\)" as a strictly monotone sequence of indices `n : ℕ → ℕ`. Note that the numerator is the gap between the two *consecutive* primes \(p_{n_i}\) and \(p_{n_i+1}\), which is `primeGap (n i)`, and not the gap between the primes indexed by two consecutive members of the sequence.
Statement as formalized in Formal Conjectures (Google DeepMind, Apache-2.0) · their label: research open · 13 further variants / known partial results in the Lean file. The authoritative wording is on erdosproblems.com/5.
Prizenone
Topicsnumber theory, primes
Statement in LeanFormal Conjectures
Solution in Leanno
OEISA001223
Original pageerdosproblems.com/5
WORKING REPORT BY THIS SITE · JUL 26, 2026

Read our working report →

Live page status OPEN; “Currently working on this problem” lists alansbor, so no attempt was made to avoid colliding with a current worker.

SKIPPED