The base size of the symmetric group acting on subsets

Coen del Valle, Colva M. Roney-Dougal

A base for a permutation group $G$ acting on a set $\Omega$ is a subset $\mathcal{B}$ of $\Omega$ such that the pointwise stabiliser $G_{(\mathcal{B})}$ is trivial. Let $n$ and $r$ be positi…