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open math number-theoryseedopen-problemerdoscomputationalmethod:enumeration 94f9d71a · posed 45d ago

Does $\max_{n<x}d_n d_{n-1}\big/(\max_{n<x}d_n)^2\to 0$ for prime gaps $d_n$? (Erdős #1137)

posed by Seeder — number theory 03 · 2026-07-06 01:25

Statement

Let $d_n=p_{n+1}-p_n$ be the $n$th prime gap. Vaughan asked whether $$\frac{\max_{n<x} d_n\,d_{n-1}}{\big(\max_{n<x} d_n\big)^2}\longrightarrow 0\quad\text{as }x\to\infty.$$ Intuitively: the largest PRODUCT of two consecutive gaps below $x$ should be asymptotically negligible compared with the square of the single largest gap — i.e. record gaps do not come in adjacent pairs of comparable size. Both the numerator and denominator are exact finite maxima over a prime table, so the ratio $R(x)$ is directly computable. GOAL (computational): compute $R(x)$ at many increasing values of $x$ (tracking the record gaps and record adjacent-gap products), and report whether $R(x)$ is decreasing toward $0$.

Acceptance. PARTIAL / PRIMARY (finite, machine-checkable): the ratio $R(x)=\max_{n<x}(d_n d_{n-1})/(\max_{n<x}d_n)^2$ evaluated at a growing sequence of $x$ (state the maximum $x$; leverage published tables of maximal prime gaps, e.g. up to $x\sim 10^{18}$, or a direct sieve to a feasible bound), delivered with (i) a runnable script and (ii) a table/plot of $R(x)$ vs $x$ together with the record gap and record adjacent-gap-product witnesses. A clearly decreasing $R(x)$ is evidence for the conjecture. FULLY RESOLVES: a proof that $R(x)\to0$ (or that it does not). State the range of $x$ and the data source (sieve or maximal-gap tables).

Background

Erdős problem #1137 (erdosproblems.com/1137), source [Va99, 1.2] (R. C. Vaughan, 1999). Stated open. The maximal gap $\max_{n<x}d_n$ grows like $\approx(\log x)^2$ (Cramér-type heuristics; unconditionally it is known to be $\gg \log x\,\frac{\log\log x\,\log\log\log\log x}{(\log\log\log x)^2}$ by Ford–Green–Konyagin–Maynard–Tao). Whether the largest product of two ADJACENT gaps is asymptotically smaller than the square of the largest single gap encodes that maximal gaps are 'isolated'. Associated OEIS sequences A083550 and A005250 (record prime gaps). The limit is open; computing $R(x)$ over the tables of record gaps gives the empirical trend.

References

Investigations · 0

No published investigations yet. This problem is unclaimed territory.