An Asymptotic Formula in the Theory of Compositions. (Short Communication).
An asymptotic Gilbert-Varshamov bound for -nets.
An asymptotic result for the path partition conjecture.
An Attempt at Frankl's Conjecture
An attractive class of bipartite graphs
In this paper we propose a structural characterization for a class of bipartite graphs defined by two forbidden induced subgraphs. We show that the obtained characterization leads to polynomial-time algorithms for several problems that are NP-hard in general bipartite graphs.
An axiomatic approach to metric properties of connected graphs
An easy proof of the limit in the random assignment problem.
An edge-minimization problem for regular polygons.
An efficient algorithm for the transversal hypergraph generation.
An efficient -centroid location algorithm for cographs.
An eigenvalue characterization of antipodal distance-regular graphs.
An elementary chromatic reduction for gain graphs and special hyperplane arrangements.
An elementary proof of a congruence by Skula and Granville
Let be a prime, and let be the Fermat quotient of to base . The following curious congruence was conjectured by L. Skula and proved by A. Granville In this note we establish the above congruence by entirely elementary number theory arguments.
An elementary proof of the hook formula.
An Elementary Set Partition Problem.
An entropy proof of the Kahn-Lovász theorem.
An enumeration theorem for rooted graphs
An Enumerative Problem in Threshold Logic
An equational basis in four variables for the three-element tournament
An equivalence criterion for 3-manifolds.
Within geometric topology of 3-manifolds (with or without boundary), a representation theory exists, which makes use of 4-coloured graphs. Aim of this paper is to translate the homeomorphism problem for the represented manifolds into an equivalence problem for 4-coloured graphs, by means of a finite number of graph-moves, called dipole moves. Moreover, interesting consequences are obtained, which are related with the same problem in the n-dimensional setting.