Results 31 to 40 of about 302 (115)
Determinantal generating functions of colored spanning forests
The color type of a spanning forest of a graph with colored edges is defined and, subsequently, it is proved that the generating function of such spanning forests is obtained as the formal expansion of a certain determinant. An analogous determinantal expansion yields the generating function of all spanning forests of a given color type that contain a ...
Gregory M. Constantine, Marius G. Buliga
wiley +1 more source
Generalized orbifold Euler characteristic of symmetric products and equivariant Morava K-theory [PDF]
We introduce the notion of generalized orbifold Euler charac- teristic associated to an arbitrary group, and study its properties. We then calculate generating functions of higher order (p-primary) orbifold Euler characteristic of symmetric products of a
Hirotaka Tamanoi
semanticscholar +1 more source
Counting occurrences of 132 in an even permutation
We study the generating function for the number of even (or odd) permutations on n letters containing exactly r ≥ 0 occurrences of a 132 pattern. It is shown that finding this function for a given r amounts to a routine check of all permutations in 𝔖2r.
Toufik Mansour
wiley +1 more source
First hitting times of simple random walks on graphs with congestion points
We derive the explicit formulas of the probability generating functions of the first hitting times of simple random walks on graphs with congestion points using group representations.
Mihyun Kang
wiley +1 more source
Equivalence classes of mesh patterns with a dominating pattern [PDF]
Two mesh patterns are coincident if they are avoided by the same set of permutations, and are Wilf-equivalent if they have the same number of avoiders of each length.
Murray Tannock, Henning Ulfarsson
doaj +1 more source
Combinatorics of geometrically distributed random variables: new q‐tangent and q‐secant numbers
Up‐down permutations are counted by tangent (respectively, secant) numbers. Considering words instead, where the letters are produced by independent geometric distributions, there are several ways of introducing this concept; in the limit they all coincide with the classical version. In this way, we get some new q‐tangent and q‐secant functions.
Helmut Prodinger
wiley +1 more source
n‐Color partitions with weighted differences equal to minus two
In this paper we study those n‐color partitions of Agarwal and Andrews, 1987, in which each pair of parts has weighted difference equal to −2 Results obtained in this paper for these partitions include several combinatorial identities, recurrence relations, generating functions, relationships with the divisor function and computer produced tables.
A. K. Agarwal, R. Balasubrananian
wiley +1 more source
Descent c-Wilf Equivalence [PDF]
Let $S_n$ denote the symmetric group. For any $\sigma \in S_n$, we let $\mathrm{des}(\sigma)$ denote the number of descents of $\sigma$, $\mathrm{inv}(\sigma)$ denote the number of inversions of $\sigma$, and $\mathrm{LRmin}(\sigma)$ denote the number of
Quang T. Bach, Jeffrey B. Remmel
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Bivariate Chromatic Polynomials of Mixed Graphs [PDF]
The bivariate chromatic polynomial $\chi_G(x,y)$ of a graph $G = (V, E)$, introduced by Dohmen-P\"{o}nitz-Tittmann (2003), counts all $x$-colorings of $G$ such that adjacent vertices get different colors if they are $\le y$. We extend this notion to
Matthias Beck, Sampada Kolhatkar
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Bicomplex generalized k-Horadam quaternions
This study provides a broad overview of the generalization of the various quaternions, especially in the context of its enhancing importance in the disciplines of mathematics and physics.
Y. Yazlık, Sure Köme, Cahit Köme
semanticscholar +1 more source