no code implementations • 23 Feb 2021 • Colin Defant
Associated to each permutation $\pi$ is a particular set $\mathcal V(\pi)$ of integer compositions that appears in a formula for the fertility of $\pi$, which is defined to be $|s^{-1}(\pi)|$.
Combinatorics 52B12, 52B40, 05A05, 05A19, 46L53
no code implementations • 7 Dec 2020 • Colin Defant
Let $s$ denote West's stack-sorting map.
Combinatorics 05A05, 05A15, 37E15
no code implementations • 27 Aug 2020 • Colin Defant, Kai Zheng
We introduce consecutive-pattern-avoiding stack-sorting maps $\text{SC}_\sigma$, which are natural generalizations of West's stack-sorting map $s$ and natural analogues of the classical-pattern-avoiding stack-sorting maps $s_\sigma$ recently introduced by Cerbai, Claesson, and Ferrari.
Combinatorics 05A05, 05A15, 37E15