منابع مشابه
Ascent-Descent Young Diagrams and Pattern Avoidance in Alternating Permutations
We investigate pattern avoidance in alternating permutations and an alternating analogue of Young diagrams. In particular, using an extension of Babson and West’s notion of shape-Wilf equivalence described in our recent paper (with N. Gowravaram), we generalize results of Backelin, West, and Xin and Ouchterlony to alternating permutations. Unlike Ouchterlony and Bóna’s bijections, our bijection...
متن کاملPattern Avoidance
Consider a sequence of letters or numbers. Does a pattern exist that is avoided by the sequence? This topic is a very popular area of research in mathematics for its promising utility in computer science and other branches of mathematics, the elegant proofs and solutions, and the many open problems that still remain. Section 1 of this paper provides definitions, notations, and some properties o...
متن کاملPattern avoidance with involution
We give the avoidance indices for all unary patterns with involution.
متن کاملGeneralised Pattern Avoidance
Recently, Babson and Steingŕımsson have introduced generalised permutation patterns that allow the requirement that two adjacent letters in a pattern must be adjacent in the permutation. We will consider pattern avoidance for such patterns, and give a complete solution for the number of permutations avoiding any single pattern of length three with exactly one adjacent pair of letters. For eight...
متن کاملExtended pattern avoidance
A 0-1 matrix is said to be extendably-avoiding if it can be the upper left corner of a-avoiding permutation matrix. This concept arose in EL], where the surprising result that the number of extendably 321-avoiding rectangles are enumerated by the ballot numbers was proved. Here we study the other ve patterns of length three. The main result is that the six patterns of length three divides into ...
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ژورنال
عنوان ژورنال: Advances in Applied Mathematics
سال: 2012
ISSN: 0196-8858
DOI: 10.1016/j.aam.2012.08.004