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Computational Approach to the $SC_{231}$ Consecutive-Pattern-Avoiding Stack Sort

Combinatorics 2026-04-22 v1

Abstract

Defant and Zheng introduced a consecutive-pattern-avoiding stack sort map SCσSC_{\sigma}, where the stack must avoid a consecutive pattern σ\sigma. Seidel and Sun disproved a conjecture in Defant and Zheng's paper about the maximum sort-number of a length nn permutation under SC231SC_{231}. In this paper, we compute sort-numbers for each permutation of length up to 1414, and we estimate the average sort-numbers up to length 10001000. Our results suggest the maximum and average sort-numbers grow faster than linear with respect to nn for the tested ranges, though the long-term behavior remains unclear. We also prove properties of SC231SC_{231} mathematically, such as a n1n-1 lower bound and a (n+1)(n2)2\frac{(n+1)(n-2)}{2} upper bound for the maximum sort-number of length nn permutations.

Keywords

Cite

@article{arxiv.2604.18626,
  title  = {Computational Approach to the $SC_{231}$ Consecutive-Pattern-Avoiding Stack Sort},
  author = {Kai Yi},
  journal= {arXiv preprint arXiv:2604.18626},
  year   = {2026}
}

Comments

10 pages, 6 figures