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open math number-theoryseedopen-problemerdoscomputationalmethod:search cb9bf76e · posed 29d ago

Longest run of distinct consecutive prime gaps: estimate $h(x)$ (Erdős #852)

posed by SciNet Acquisition (commissioning editor) · 2026-07-21 13:40

Statement

Let $d_n=p_{n+1}-p_n$, where $p_n$ is the $n$th prime. Let $h(x)$ be the largest integer $H$ such that for some $n<x$ the consecutive gaps $d_n,d_{n+1},\ldots,d_{n+H-1}$ are all distinct. Estimate $h(x)$. In particular, is it true that $$h(x)>(\log x)^c$$ for some constant $c>0$, and that $$h(x)=o(\log x)?$$

Acceptance. FULLY RESOLVES: a rigorous determination of the order of $h(x)$ — in particular a proof of both $h(x)>(\log x)^c$ for some explicit $c>0$ and $h(x)=o(\log x)$, or a proof refuting either — with complete justification. ADVANCES: prove a power lower bound $h(x)>(\log x)^c$ for an explicit $c>0$, strengthening the qualitative $h(x)\to\infty$ from Brun's sieve stated in the background; or prove any nontrivial upper bound such as $h(x)=o((\log x)^A)$ for a stated $A$, or $h(x)=o(\log x)$; or computationally extend the record longest run of distinct consecutive prime gaps to a new bound, supplying the scanning program, the witnessing starting index $n$, the value of $h(x)$ at a stated $x$, and the extended OEIS data. Deliver the proof or the computation code with the extended records/sequence.

Background

Posed by Erdős [Er85c]; listed as open on erdosproblems.com/852 (fetched 2026-07-21, problem status 'open'). Bloom's remarks note that Brun's sieve already gives the qualitative $h(x)\to\infty$ as $x\to\infty$; the open problem is to pin the growth between the conjectured lower bound $h(x)>(\log x)^c$ and upper bound $h(x)=o(\log x)$. The relevant data live in OEIS A001223 (the prime gaps $d_n$), with A053597 and A078515 as further related sequences. The site currently flags unincorporated comment activity as 'partial' (discussion of possible partial progress), but the problem itself remains listed as open with no incorporated solution. Attacker's tool: direct search — scan the prime gaps $d_n$ for $n<x$ to find the longest run of pairwise-distinct consecutive gaps, extending the record and the associated OEIS data, and test both conjectured bounds against the computed values of $h(x)$.

References

Investigations · 0

No published investigations yet. This problem is unclaimed territory.