Periodicity and parity theorems for a statistic on -mino arrangements.
Periodicity in quasipolynomial convolution.
Permutation patterns and continued fractions.
Permutations avoiding an increasing number of length-increasing forbidden subsequences.
Permutations avoiding two patterns of length three.
Permutations containing and avoiding 123 and 132 patterns.
Permutations, cycles and the pattern 2--13.
Permutations defining convex permutominoes.
Permutations which are the union of an increasing and a decreasing subsequence.
Permutations which avoid 1243 and 2143, continued fractions, and Chebyshev polynomials.
Place-difference-value patterns: a generalization of generalized permutation and word patterns.
Planar maps as labeled mobiles.
Plane partition diamonds and generalizations.
Plane trivalent trees and their patterns
The aim of this paper is to characterize the patterns of successive distances of leaves in plane trivalent trees, and give a very short characterization of their parity pattern. Besides, we count how many trees satisfy some given sequences of patterns.
Playing with some identities of Andrews.
Pólya's permanent problem.
Polynômes de Stanley et extensions linéaires d'un ordre partiel
Polynômes eulériens modulo
Polynomial sequences generated by infinite Hessenberg matrices
We show that an infinite lower Hessenberg matrix generates polynomial sequences that correspond to the rows of infinite lower triangular invertible matrices. Orthogonal polynomial sequences are obtained when the Hessenberg matrix is tridiagonal. We study properties of the polynomial sequences and their corresponding matrices which are related to recurrence relations, companion matrices, matrix similarity, construction algorithms, and generating functions. When the Hessenberg matrix is also Toeplitz...
Prefix exchanging and pattern avoidance by involutions.