Unsplittable Classes of Separable Permutations
نویسندگان
چکیده
منابع مشابه
Unsplittable Classes of Separable Permutations
A permutation class is splittable if it is contained in the merge of two of its proper subclasses. We characterise the unsplittable subclasses of the class of separable permutations both structurally and in terms of their bases.
متن کاملEquipopularity Classes in the Separable Permutations
When two patterns occur equally often in a set of permutations, we say that these patterns are equipopular. Using both structural and analytic tools, we classify the equipopular patterns in the set of separable permutations. In particular, we show that the number of equipopularity classes for length n patterns in the separable permutations is equal to the number of partitions of the integer n− 1.
متن کاملSubclasses of the Separable Permutations
The separable permutations are those that can be obtained from the trivial permutation by two operations called direct sum and skew sum. This class of permutations contains the class of stack sortable permutations,Avp231q, which are enumerated by the Catalan numbers. We prove that all subclasses of the separable permutations which do not contain Avp231q or a symmetry of this class have rational...
متن کاملYoung classes of permutations
We characterise those classes of permutations closed under taking subsequences and reindexing that also have the property that for every tableau shape either every permutation of that shape or no permutation of that shape belongs to the class. The characterisation is in terms of the dominance order for partitions (and their conjugates) and shows that for any such class there is a constant k suc...
متن کاملPattern Classes of Permutations
Though still a relatively young subject within discrete mathematics, the study of pattern classes of permutations is one of the fastest growing and is useful in theoretical computer science as well as various areas of mathematics. There are two commonly used forms of notation for permutations: a1a2 . . . an denotes the permutation which sends i to ai for i = 1, 2, . . . , n, where each ai repre...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: The Electronic Journal of Combinatorics
سال: 2016
ISSN: 1077-8926
DOI: 10.37236/6115