29 citations · 254 across the 72 of their papers we have counts for
5 papers · 2 filters
Restricted Motzkin permutations, Motzkin paths, continued fractions, and Chebyshev polynomials
Sergi Elizalde, Toufik Mansour
We say that a permutation is a Motzkin permutation if it avoids 132 and there do not exist such that . We study the distribution of several statistics in…
Restricted Dumont permutations, Dyck paths, and noncrossing partitions
Alexander Burstein, Sergi Elizalde, Toufik Mansour
We complete the enumeration of Dumont permutations of the second kind avoiding a pattern of length 4 which is itself a Dumont permutation of the second kind. We also consider some…
Partially ordered patterns and compositions
Silvia Heubach, Sergey Kitaev, Toufik Mansour
A partially ordered (generalized) pattern (POP) is a generalized pattern some of whose letters are incomparable, an extension of generalized permutation patterns introduced by Babs…
Wilf classification of three and four letter signed patterns
W. M. B. Dukes, T. Mansour, A. Reifegerste
We give some new Wilf equivalences for signed patterns which allow the complete classification of signed patterns of lengths three and four. The problem is considered for pattern a…
Grid polygons from permutations and their enumeration by the kernel method
Toufik Mansour, Simone Severini
A grid polygon is a polygon whose vertices are points of a grid. We define an injective map between permutations of length n and a subset of grid polygons on n vertices, which we c…