8 citations · 10 across the 5 of their papers we have counts for
7 papers
Involutions Restricted by 3412, Continued Fractions, and Chebyshev Polynomials
Eric Egge, Toufik Mansour
We study generating functions for the number of involutions, even involutions, and odd involutions in subject to two restrictions. One restriction is that the involution avoi…
Restricted 3412-Avoiding Involutions: Continued Fractions, Chebyshev Polynomials and Enumerations
Eric S. Egge
Several authors have examined connections among restricted permutations, continued fractions, and Chebyshev polynomials of the second kind. In this paper we prove analogues of thes…
231-Avoiding Involutions and Fibonacci Numbers
Eric S. Egge, Toufik Mansour
We use combinatorial and generating function techniques to enumerate various sets of involutions which avoid 231 or contain 231 exactly once. Interestingly, many of these enumerati…
Permutations Which Avoid 1243 and 2143, Continued Fractions, and Chebyshev Polynomials
Eric S. Egge, Toufik Mansour
Several authors have examined connections between permutations which avoid 132, continued fractions, and Chebyshev polynomials of the second kind. In this paper we prove analogues…
132-avoiding Two-stack Sortable Permutations, Fibonacci Numbers, and Pell Numbers
Eric S. Egge, Toufik Mansour
In 1990 West conjectured that there are two-stack sortable permutations on letters. This conjecture was proved analytically by Zeilberger in 1992. Late…
Restricted Permutations, Fibonacci Numbers, and k-generalized Fibonacci Numbers
Eric S. Egge, Toufik Mansour
A permutation is said to {\it avoid} a permutation whenever contains no subsequence with all of the same pairwise comparisons as . For any set of p…