Wilf-Classification of Mesh Patterns of Short Length

[摘要] This paper starts the Wilf-classification of mesh patterns of length 2. Although there are initially 1024 patterns to consider we introduce automatic methods to reduce the number of potentially different Wilf-classes to at most 65. By enumerating some of

[学科分类] 离散数学和组合数学

[关键词] Permutations;Pattern avoidance;Generating functions