A remark on self-centroidal graphs
A remark on signed posets and signed graphs
A remark on systems of maximal cliques of a graph
A remark on the (2,2)-domination number
A subset D of the vertex set of a graph G is a (k,p)-dominating set if every vertex v ∈ V(G)∖D is within distance k to at least p vertices in D. The parameter denotes the minimum cardinality of a (k,p)-dominating set of G. In 1994, Bean, Henning and Swart posed the conjecture that for any graph G with δₖ(G) ≥ k+p-1, where the latter means that every vertex is within distance k to at least k+p-1 vertices other than itself. In 2005, Fischermann and Volkmann confirmed this conjecture for all integers...
A remark on -regular orthomodular lattices
A finite orthomodular lattice in which every maximal Boolean subalgebra (block) has the same cardinality is called -regular, if each atom is a member of just blocks. We estimate the minimal number of blocks of -regular orthomodular lattices to be lower than of equal to regardless of .
A reminiscence about shortest spanning subtrees
A representation of Sheffer polynomials in terms of a differential equation for their generating functions.
A representation of Sheffer polynomials in terms of a differential equation for their generating functions. (Short Communication).
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.