English

$K$ block set partition patterns and statistics

Combinatorics 2020-03-09 v1

Abstract

A set partition σ\sigma of [n]={1,,n}[n]=\{1,\cdots ,n\} contains another set partition ω\omega if a standardized restriction of σ\sigma to a subset S[n]S\subseteq[n] is equivalent to ω\omega. Otherwise, σ\sigma avoids ω\omega. Sagan and Goyt have determined the cardinality of the avoidance classes for all sets of patterns on partitions of [3][3]. Additionally, there is a bijection between the set partitions and restricted growth functions (RGFs). Wachs and White defined four fundamental statistics on those RGFs. Sagan, Dahlberg, Dorward, Gerhard, Grubb, Purcell, and Reppuhn consider the distributions of these statistics over various avoidance classes and they obtained four variate analogues of the previously cited cardinality results. They did the first thorough study of these distributions. The analogues of their many results follows for set partitions with exactly kk blocks for a specified positive integer kk. These analogues are discussed in this work.

Keywords

Cite

@article{arxiv.2003.02915,
  title  = {$K$ block set partition patterns and statistics},
  author = {Amrita Acharyya and Robinson Paul Czajkowski and Allen Richard Williams},
  journal= {arXiv preprint arXiv:2003.02915},
  year   = {2020}
}

Comments

Original Research

R2 v1 2026-06-23T14:05:47.313Z