Using functional equations to enumerate 1324-avoiding permutations
نویسندگان
چکیده
منابع مشابه
Using functional equations to enumerate 1324-avoiding permutations
We consider the problem of enumerating permutations with exactly r occurrences of the pattern 1324 and derive functional equations for this general case as well as for the pattern avoidance (r = 0) case. The functional equations lead to a new algorithm for enumerating length n permutations that avoid 1324. This approach is used to enumerate the 1324-avoiders up to n = 31. We also extend those f...
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The class Av(1324), of permutations avoiding the pattern 1324, is one of the simplest sets of combinatorial objects to define that has, thus far, failed to reveal its enumerative secrets. By considering certain large subsets of the class, which consist of permutations with a particularly regular structure, we prove that the growth rate of the class exceeds 9.81. This improves on a previous lowe...
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ژورنال
عنوان ژورنال: Advances in Applied Mathematics
سال: 2014
ISSN: 0196-8858
DOI: 10.1016/j.aam.2014.01.006