29 citations · 159 across the 40 of their papers we have counts for
10 papers · 1 filter
A comment on Ryser's conjecture for intersecting hypergraphs
Toufik Mansour, Chunwei Song, Raphael Yuster
Let be the cover number and be the matching number of a hypergraph . Ryser conjectured that every -partite hypergraph $\mathcal{H}…
Partial transpose of permutation matrices
Qing-Hu Hou, Toufik Mansour, Simone Severini
The partial transpose of a block matrix M is the matrix obtained by transposing the blocks of M independently. We approach the notion of partial transpose from a combinatorial poin…
New equivalences for pattern avoiding involutions
Mark Dukes, Vit Jelínek, Toufik Mansour +1
We complete the Wilf classification of signed patterns of length 5 for both signed permutations and signed involutions. New general equivalences of patterns are given which prove J…
Motzkin numbers of higher rank: Generating function and explicit expression
Toufik Mansour, Matthias Schork, Yidong Sun
The generating function and an explicit expression is derived for the (colored) Motzkin numbers of higher rank introduced recently. Considering the special case of rank one yields…
Combinatorial Gray codes for classes of pattern avoiding permutations
W. M. B. Dukes, Mark F. Flanagan, Toufik Mansour +1
The past decade has seen a flurry of research into pattern avoiding permutations but little of it is concerned with their exhaustive generation. Many applications call for exhausti…
On pattern-avoiding partitions
Vit Jelinek, Toufik Mansour
A \emph{set partition} of the set is a collection of disjoint blocks whose union is . We choose the ordering of the blocks so that they…