On an open problem of Green and Losonczy: exact enumeration of freely braided permutations
نویسنده
چکیده
Recently, Green and Losonczy [5, 6] introduced freely braided permutations as a special class of restricted permutations that has arisen in the study of Schubert varieties. They suggest as an open problem to enumerate the number of freely braided permutations in Sn. In this paper, we prove that the generating function for the number of freely braided permutations in Sn is given by 1−3x−2x2 +(1+ x) √ 1−4x 1−4x− x2 +(1− x2) √ 1−4x .
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ورودعنوان ژورنال:
- Discrete Mathematics & Theoretical Computer Science
دوره 6 شماره
صفحات -
تاریخ انتشار 2004