2024/07/08 by Archer, Kassie, Laudone, Robert P. · 1 citation
#Combinatorics (math.CO) #FOS: Mathematics
paper · doi:10.48550/arxiv.2407.06338
The fundamental bijection is a bijection θ:Sn\toSn in which one uses the standard cycle form of one permutation to obtain another permutation in one-line form. In this paper, we enumerate the set of permutations π∈ Sn that avoids a pattern σ∈ S3, whose image θ(π) also avoids σ. We additionally consider what happens under repeated iterations of θ; in particular, we enumerate permutations π∈ Sn that have the property that π and its first k iterations under θ all avoid a pattern σ. Finally, we consider permutations with the property that π=θ2(π) that avoid a given pattern σ, and end the paper with some directions for future study.