Une généralisation trivariée symétrique des nombres eulériens

Une généralisation automorphe des nombres de Stirling

Let [n] be theset {1,2, *.. , n> and CT a given permutation in S,, the symmetric group on [n]. The (unsigned) Stirling numbers of the first kind enumerate the permutations on En] with k cycles and those of the second kind give the number partitions of [n] having k blocks. In this paper we compute the number of permutations on [n] with k cycles and the number of partitions on [n] having k blocks...

Sur une Généralisation des Coefficients Binomiaux

We prove a recent conjecture of Lassalle about positivity and integrality of coefficients in some polynomial expansions. We also give a combinatorial interpretation of those numbers. Finally, we show that this question is closely related to the fundamental problem of calculating the linearization coefficients for binomial coefficients.

Pour une généralisation des systèmes C.A.O : approche et applications

Une Base Symétrique de l'Algèbre des Coinvariants Quasi-Symétriques

We describe a new basis of the ring of quasi-symmetric coinvariants, which is stable by the natural reversal of the set of variables. The indexing set is the set of triangulations of a regular polygon, instead of the set of Dyck paths used for the known basis.

GWUM : une généralisation des pages Web guidée par les usages

The usage analysis of a Web site based on the extracted sequential patterns is often limited by the low support of these patterns. That is mainly due to the great diversity of the pages and behaviors. However, it is possible to group the majority of these pages in various categories during a preprocessing. Then, using these categories, rather than the URL, will allow us to discover "generic" be...