A restricted random walk defined via a Fibonacci process.
A result on co-chromatic graphs.
A result on -critical graphs.
A result related to the largest eigenvalue of a tree
In this note we prove that {0,1,√2,√3,2} is the set of all real numbers l such that the following holds: every tree having an eigenvalue which is larger than l has a subtree whose largest eigenvalue is l.
A Riordan array proof of a curious identity.
A Schröder generalization of Haglund's statistic on Catalan paths.
A semigroup approach to wreath-product extensions of Solomon's descent algebras.
A Sequence of Exponential Numbers
A series transformation formula and related polynomials.
A service points location problem with Min-Max distance optimality criterion
A sextuple product identity with applications.
A sharp bound for the reconstruction of partitions.
A sharp inequality involving the psi function.
A sharp upper bound for the spectral radius of a nonnegative matrix and applications
We obtain a sharp upper bound for the spectral radius of a nonnegative matrix. This result is used to present upper bounds for the adjacency spectral radius, the Laplacian spectral radius, the signless Laplacian spectral radius, the distance spectral radius, the distance Laplacian spectral radius, the distance signless Laplacian spectral radius of an undirected graph or a digraph. These results are new or generalize some known results.
A short proof, based on mixed volumes, of Liggett's theorem on the convolution of ultra-logconcave sequences.
A short proof of a partion relation for triples.
A short proof of a series evaluation in terms of harmonic numbers.
A short proof of a theorem of Kano and Yu on factors in regular graphs.
A short proof of an identity of Sylvester.
A short proof of rigidity of convex polytopes.