author: | Toufik Mansour |
---|---|
title: | On an open problem of Green and Losonczy: exact enumeration of freely braided permutations |
keywords: | restricted permutations, freely braided permutations, generating functions |
abstract: | Recently, Green and Losonczy GL1,GL2 introduced freely braided permutation as a special class of restricted permutations has arisen in representation theory. The freely braided
permutations were introduced and studied as the upper bound for
the number of commutation classes of reduced expressions for an
element of a simply laced Coxeter group is achieved if and only if
when the element is freely braided. 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
If your browser does not display the abstract correctly (because of the different mathematical symbols) you can look it up in the PostScript or PDF files. |
reference: | Toufik Mansour (2004), On an open problem of Green and Losonczy: exact enumeration of freely braided permutations, Discrete Mathematics and Theoretical Computer Science 6, pp. 461-470 |
bibtex: | For a corresponding BibTeX entry, please consider our BibTeX-file. |
ps.gz-source: | dm060218.ps.gz (41 K) |
ps-source: | dm060218.ps (120 K) |
pdf-source: | dm060218.pdf (84 K) |
The first source gives you the `gzipped' PostScript, the second the plain PostScript and the third the format for the Adobe accrobat reader. Depending on the installation of your web browser, at least one of these should (after some amount of time) pop up a window for you that shows the full article. If this is not the case, you should contact your system administrator to install your browser correctly.
Due to limitations of your local software, the two formats may show up differently on your screen. If eg you use xpdf to visualize pdf, some of the graphics in the file may not come across. On the other hand, pdf has a capacity of giving links to sections, bibliography and external references that will not appear with PostScript.