PROVED (LEAN)
This has been solved in the affirmative and the proof verified in Lean.
Let $S(n)$ denote the largest integer such that, for all $1\leq k<n$, the binomial coefficient $\binom{n}{k}$ is divisible by $p^{S(n)}$ for some prime $p$ (depending on $k$). Is it true that\[\limsup S(n)=\infty?\]
If $s(n)$ denotes the largest integer such that $\binom{n}{k}$ is divisible by $p^{s(n)}$ for some prime $p$ for at least one $1\leq k<n$ then it is easy to see that $s(n)\to \infty$ as $n\to \infty$ (and in fact that $s(n) \asymp \log n$).
This problem was solved in the affirmative by Cambie, Kovač, and Tao (see the comment section). A Lean formalisation of their proof is available
here.
There are other simpler constructions: for example, $3^{2^k}$ for arbitrarily large $k$ (see
this discussion).
See also
[175].
View the LaTeX source
This page was last edited 12 January 2026. View history
Additional thanks to: marinov
When referring to this problem, please use the original sources of Erdős. If you wish to acknowledge this website, the recommended citation format is:
T. F. Bloom, Erdős Problem #379, https://www.erdosproblems.com/379, accessed 2026-08-09
0 claimed proofs for this problem