A graph G on n vertices is Hamiltonian if it contains a cycle of length n and pancyclic if it contains cycles of length for all 3 ≤ ≤ n. Write α(G) for the independence numbe...
The vertex Folkman number F(r, n, m), n < m, is the smallest integer t such that there exists a Km-free graph of order t with the property that every r-coloring of its vertices...
Abstract. We present bijections between four classes of combinatorial objects. Two of them, the class of unlabeled (2 + 2)-free posets and a certain class of involutions (or chord ...
For k > 2 and r ≥ 2, let G(k, r) denote the smallest positive integer g such that every increasing sequence of g integers {a1, a2, . . . , ag} with gaps aj+1 − aj ∈ {1, ....
We propose a major index statistic on 01-fillings of moon polyominoes which, when specialized to certain shapes, reduces to the major index for permutations and set partitions. W...
William Y. C. Chen, Svetlana Poznanovic, Catherine...