Andrew Beveridge

works on

fibonacci enumeration 1 lehmer codes 1 permutation patterns 1 poset structure 1 reverse-complement bijection 1

From the 1 of 6 linked papers with an AI index.

collaborators

6 papers

math.CO2026

Lehmer Codes and the Reverse-Complement Mapping from (32-1)-Avoiding Permutations to (3-21)-Avoiding Permutations

Andrew Beveridge, Yufan Hu, Yucheng Liu

The paper uses Lehmer codes to model permutations avoiding the vincular patterns 32‑1 and 3‑21 as weighted posets, shows that the maximal elements of these posets are counted by Fi…

math.CO2026

(32-1)-Avoiding Permutations with Maximum Inversion Number

Andrew Beveridge, Kristin Heysse, Paige Robertson

A permutation $I ¨ \in S_{n}$ is (32-1)-avoiding when there do not exist $1 \leq i < i + 1 < j \leq n$ such that $I ¨ _{i} > I ¨ _{i + 1} > I ¨ _{j}$ . We determine the maximum inversion number for (…

math.CO2026

Approval Ballot Triangles and Strict-Sense Ballots

Andrew Beveridge, Ian Calaway

We consider a family of binary triangular arrays, called approval ballot triangles (ABTs), that are in bijection with totally symmetric self-complementary plane partitions (TSSCPPs…

math.CO2025

Random Walks and the Best Meeting Time for Trees

Andrew Beveridge, Ari Holcombe Pomerance

We consider random walks on a tree $G = (V, E)$ with stationary distribution $I ¨ _{v} = deg (v) /2∣ E ∣$ for $v \in V$ . Let the hitting time $H (v, w)$ denote the expected number of s…

math.CO2025

Random Walks and the Meeting Time for Trees

Andrew Beveridge, Ben Bridenbaugh, Ari Holcombe Pomerance

Consider a random walk on a tree $G = (V, E)$ . For $v, w \in V$ , let the hitting time $H (v, w)$ denote the expected number of steps required for the random walk started at $v$ to reach…

math.CO2025

The Exact Mixing Time for Trees with Fixed Diameter

Andrew Beveridge, Kristin Heysse, Rhys O'Higgins +1

We characterize the extremal structure for the exact mixing time for random walks on trees $T_{n, d}$ of order $n$ with diameter $d$ . Given a graph $G = (V, E)$ , let $H (v, I ¨ )$ denote t…