29 citations · 206 across the 48 of their papers we have counts for
5 papers · 2 filters
Restricted single or double signed patterns
T. Mansour
Let be the set of all signed permutations on the symbols 1,2,...,n with signs 1,2,...,r. We prove, for e…
Restricted 132-avoiding permutations
T. Mansour, A. Vainshtein
We study generating functions for the number of permutations on n letters avoiding 132 and an arbitrary permutation on k letters, or containing exactly once. In several int…
Layered restrictions and Chebyshev polynomials
T. Mansour, A. Vainshtein
A permutation is called layered if it consists of the disjoint union of substrings (layers) so that the entries decrease within each layer, and increase between the layers. We find…
Permutations avoiding a pattern from and at least two patterns from
T. Mansour
In this paper, we find explicit formulas or generating functions for the cardinalities of the sets of all permutations in that avoid a pattern and a set…
Avoiding maximal parabolic subgroups of S_k
Toufik Mansour, Alek Vainshtein
We find an explicit expression for the generating function of the number of permutations in S_n avoiding a subgroup of S_k generated by all but one simple transpositions. The gener…