Growth rates for subclasses of Av(321)

Abstract

Pattern classes which avoid 321 and other patterns are shown to have the same growth rates as similar (but strictly larger) classes obtained by adding articulation points to any or all of the other patterns. The method of proof is to show that the elements of the latter classes can be represented as bounded merges of elements of the original class, and that the bounded merge construction does not change growth rates.

20 pages, 5 figures

References in corpus (1)

• Permutation classes of every growth rate above 2.48188

Cited by in corpus (6)

• Upper bounds for the Stanley-Wilf limit of 1324 and other layered patterns
• The enumeration of permutations avoiding 2143 and 4231
• Deflatability of Permutation Classes
• Patterns in Permutations and Involutions: A Structural and Enumerative Approach
• Fillings of skew shapes avoiding diagonal patterns
• An algorithm for deciding the finiteness of the number of simple permutations in permutation classes