Problem Statement
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\[\limsup S(n)=\infty?\]
Categories:
Number Theory Binomial Coefficients
Progress
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].
Source: erdosproblems.com/379 | Last verified: January 14, 2026