close
Dual View Random Solved Random Open
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

External data from the database - you can help update this
Formalised statement? Yes
Related OEIS sequences: Possible
Likes this problem Vjeko_Kovac
Interested in collaborating None
Currently working on this problem None
This problem looks difficult None
This problem looks tractable None
The results on this problem could be formalisable None
I am working on formalising the results on this problem None

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