The Order of Points on the Second Convex Hull of a Simple Polygon.
The packing density of other layered permutations.
The Parity of Permutations.
The permutation classes equinumerous to the smooth class.
The reciprocal super Catalan matrix
The reciprocal super Catalan matrix has entries [...] . Explicit formulæ for its LU-decomposition, the LU-decomposition of its inverse, and some related matrices are obtained. For all results, q-analogues are also presented.
The Schubert calculus of decomposable permutations. (Le calcul de Schubert des permutations décomposables.)
The semigroup of fully indecomposable relations and Hall relations
The size of Fulton's essential set.
The skew and relative derangements of type B.
The visibility parameter for words and permutations
We investigate the visibility parameter, i.e., the number of visible pairs, first for words over a finite alphabet, then for permutations of the finite set {1, 2, …, n}, and finally for words over an infinite alphabet whose letters occur with geometric probabilities. The results obtained for permutations correct the formula for the expectation obtained in a recent paper by Gutin et al. [Gutin G., Mansour T., Severini S., A characterization of horizontal visibility graphs and combinatorics on words,...
Théorie des permutations et des arrangements circulaires complets
There are no Golay complementary sequences of length 2.9t.
Three Notes on Permutations.
Three-letter-pattern avoiding permutations and functional equations.
Two game-set inequalities.
Two involutions for signed excedance numbers.