Results 61 to 70 of about 11,738 (234)

The local $h$-vector of the cluster subdivision of a simplex [PDF]

, 2012
The cluster complex $\Delta (\Phi)$ is an abstract simplicial complex, introduced by Fomin and Zelevinsky for a finite root system $\Phi$. The positive part of $\Delta (\Phi)$ naturally defines a simplicial subdivision of the simplex on the vertex set of
Athanasiadis, Christos A., Savvidou, Christina   +1 more
core   +2 more sources

Strong External Difference Families and Classification of α‐Valuations

Journal of Combinatorial Designs, Volume 33, Issue 9, Page 343-356, September 2025.
ABSTRACT One method of constructing ( a 2 + 1 , 2 , a , 1 )‐SEDFs (i.e., strong external difference families) in Z a 2 + 1 makes use of α‐valuations of complete bipartite graphs K a , a. We explore this approach and we provide a classification theorem which shows that all such α‐valuations can be constructed recursively via a sequence of “blow‐up ...
Donald L. Kreher, Maura B. Paterson, Douglas R. Stinson   +2 more
wiley   +1 more source

History of Catalan numbers [PDF]

, 2014
We give a brief history of Catalan numbers, from their first discovery in the 18th century to modern times. This note will appear as an appendix in Richard Stanley's forthcoming book on Catalan numbers.Comment: 10 ...
Pak, Igor
core   +1 more source

Enumeration and Construction of Row‐Column Designs

Journal of Combinatorial Designs, Volume 33, Issue 9, Page 357-372, September 2025.
ABSTRACT We computationally completely enumerate a number of types of row‐column designs up to isotopism, including double, sesqui, and triple arrays as known from the literature, and two newly introduced types that we call mono arrays and AO‐arrays. We calculate autotopism group sizes for the designs we generate.
Gerold Jäger, Klas Markström, Denys Shcherbak, Lars‐Daniel Öhman   +3 more
wiley   +1 more source

C-Finite Sequences and Riordan Arrays

Mathematics
Many prominent combinatorial sequences, such as the Fibonacci, Lucas, Pell, Jacobsthal and Tribonacci sequences, are defined by homogeneous linear recurrence relations with constant coefficients.
Donatella Merlini
doaj   +1 more source

Construction of Bernstein‐Based Words and Their Patterns

Mathematical Methods in the Applied Sciences, Volume 48, Issue 13, Page 12819-12836, September 2025.
ABSTRACT In this paper, with inspiration of the definition of Bernstein basis functions and their recurrence relation, we give construction of a new word family that we refer Bernstein‐based words. By classifying these special words as the first and second kinds, we investigate their some fundamental properties involving periodicity and symmetricity ...
Irem Kucukoglu, Yilmaz Simsek
wiley   +1 more source

On the sub-permutations of pattern avoiding permutations

, 2014
There is a deep connection between permutations and trees. Certain sub-structures of permutations, called sub-permutations, bijectively map to sub-trees of binary increasing trees.
Disanto, Filippo, Wiehe, Thomas
core   +1 more source

Quantification and Determination of Compatible Bacterial Consortia

Microbial Biotechnology, Volume 18, Issue 9, September 2025.
This study presents a mathematical model to identify compatible bacterial consortia by analysing antagonistic and coexistence relationships. Introducing the Bacterial Coexistence Index (BCI), it evaluates bacterial viability. The model identified 36,851 strain sets promoting plant growth, optimising bacterial consortium design for sustainable ...
Jair J. Pineda‐Pineda, Jesús Muñoz‐Rojas, Yolanda E. Morales‐García, Esperanza Trenado‐Sánchez, José M. Sigarreta   +4 more
wiley   +1 more source

Conformal Hypergraphs: Duality and Implications for the Upper Clique Transversal Problem

Journal of Graph Theory, Volume 109, Issue 4, Page 466-480, August 2025.
ABSTRACT Given a hypergraph ℋ, the dual hypergraph of ℋ is the hypergraph of all minimal transversals of ℋ. The dual hypergraph is always Sperner, that is, no hyperedge contains another. A special case of Sperner hypergraphs are the conformal Sperner hypergraphs, which correspond to the families of maximal cliques of graphs.
Endre Boros, Vladimir Gurvich, Martin Milanič, Yushi Uno   +3 more
wiley   +1 more source

Thom series of contact singularities [PDF]

, 2010
Thom polynomials measure how global topology forces singularities. The power of Thom polynomials predestine them to be a useful tool not only in differential topology, but also in algebraic geometry (enumerative geometry, moduli spaces) and algebraic ...
Fehér, L. M., Rimányi, R.
core