Let Pn and Qn be the polynomials obtained by repeated differentiation of the tangent and secant functions respectively. From the exponential generating functions of these polynomia...
A spanning subgraph H of a graph G is a 2-detour subgraph of G if for each x, y V (G), dH (x, y) dG(x, y) + 2. We prove a conjecture of Erdos, Hamburger, Pippert, and Weakley by ...
Let Q(N) denote the number of partitions of N into distinct parts. If ω(k) := 3k2 +k 2 , then it is well known that Q(N) + ∞X k=1 (−1)k “ Q(N − 2ω(k)) + Q(N − 2ω(−k)...
Let Qn be a hypercube of dimension n, that is, a graph whose vertices are binary n-tuples and two vertices are adjacent iff the corresponding n-tuples differ in exactly one posit...
Maria Axenovich, Heiko Harborth, Arnfried Kemnitz,...