Skip to content

Erdős problem 390

Let f(n)f(n) be the least mm for which n!n! can be written as a1aka_1\cdots a_k with n<a1<<ak=mn < a_1 < \cdots < a_k = m - the smallest possible largest factor in a factorization of n!n! into distinct integers all exceeding nn. Erdős, Guy and Selfridge proved f(n)2nn/lognf(n) - 2n \asymp n/\log n. Erdős asked whether there is a constant cc with f(n)2ncnlogn,f(n) - 2n \sim c\,\frac{n}{\log n}, and what it is.

No current result

No reviewed Result is current in Vela Mathematics Program. Retained source material is shown below.

Retained declaration

FormalConjectures/ErdosProblems/390.lean

Formal Conjectures

FormalConjectures/ErdosProblems/390.leanErdos390.erdos_3901 lineExact file
True ↔ ∃ c, Asymptotics.IsEquivalent Filter.atTop (fun n => ↑(Erdos390.f n) - 2 * ↑n) fun n => c * ↑n / Real.logn
OpenStatement only, no proof

Reported activity

Work these sources record against this Problem. Source-reported attribution, not reviewed here.

  • AI collaborating with humans

    Erdős AI contributions wiki · 2 May, 2026

    Machine
    GPT-5.5 Pro
    People
    Samuel Mausberg
    Open the source record
  • argument

    VibeMathed

    Machine
    ChatGPT 5.6
    People
    Shouqiao Wang
    Reported outcome
    candidate
    Open the source record

Continue

Search problems.science

Find a Problem, Result, source, or page