Longest alternating subsequences in pattern-restricted k-ary words
نویسنده
چکیده
We study the generating functions for pattern-restricted k-ary words of length n corresponding to the longest alternating subsequence statistic in which the pattern is any one of the six permutations of length three.
منابع مشابه
Longest alternating subsequences of k-ary words
Recently, Stanley [Longest alternating subsequences of permutations, preprint, arXiv/0511419v1] studied the length of the longest alternating subsequence of a permutation in the symmetric group,where a sequencea, b, c, d, . . . isalternating ifa >bd < · · ·. In this paper, we extend this result to the case of k-ary words. More precisely, we find an explicit formula for the generating functio...
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