نتایج جستجو برای: rook

تعداد نتایج: 423  

1996
James Haglund JAMES HAGLUND

The number of ways of placing k non-attacking rooks on a Ferrers board is expressed as a hypergeometric series, of a type originally studied by Karlsson and Minton. Known transformation identities for series of this type translate into new theorems about rook polynomials.

Journal: :iranian journal of parasitology 0
a halajian department of parasitology, faculty of specialized veterinary sciences, science and research branch, islamic azad university, tehran, iran a eslami department of parasitology, faculty of specialized veterinary sciences, science and research branch, islamic azad university, tehran, iran i mobedi department of medical parasitology and mycology, school of public health, tehran university of medical sciences, iran o amin department of medical parasitology and mycology, school of public health, tehran university of medical sciences, iran j mariaux curator department of invertebrates, natural history museum, geneva, switzerland j mansoori department of environment, islamic azad university, tonekabon branch, mazandaran, iran

background: corvidae is a cosmopolitan family of oscine birds including crows, rooks, mag­pies, jays, chough, and ravens. these birds are migratory species, especially in the shortage of foods, so they can act like vectors for a wide range of microorganisms. they live generally in temper­ate climates and in a very close contact with human residential areas as well as poultry farms. there is no ...

2010
Mike Develin Jeremy L. Martin Victor Reiner

K. Ding studied a class of Schubert varieties Xλ in type A partial flag manifolds, indexed by integer partitions λ and in bijection with dominant permutations. He observed that the Schubert cell structure of Xλ is indexed by maximal rook placements on the Ferrers board Bλ, and that the integral cohomology groups H∗(Xλ; Z), H ∗(Xμ; Z) are additively isomorphic exactly when the Ferrers boards Bλ,...

Journal: :J. Comb. Theory, Ser. A 2000
Jay Goldman James Haglund

Generalizing the notion of placing rooks on a Ferrers board leads to a new class of combinatorial models and a new class of rook polynomials. Connections are established with absolute Stirling numbers and permutations, Bessel polynomials, matchings, multiset permutations, hypergeometric functions, Abel polynomials and forests, and polynomial sequences of binomial type. Factorization and recipro...

Journal: :European Journal of Combinatorics 2019

Journal: :Communications in Algebra 2013

Journal: :Bulletin of Mathematical Sciences 2012

2010
Brian K. Miceli

We define a generalization of the Stirling numbers of the first and second kinds and develop a new rook theory model to give combinatorial interpretations to these numbers. These rook-theoretic interpretations are used to give a direct combinatorial proof that two associated matrices are inverses of each other. We also give combinatorial interpretations of the numbers in terms of certain collec...

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