Abstract. The Legendre-Stirling numbers were discovered in 2002 as a result of a problem involving the spectral theory of powers of the classical second-order Legendre di¤erential...
George E. Andrews, Wolfgang Gawronski, Lance L. Li...
The World Wide Web may be viewed as a graph each of whose vertices corresponds to a static HTML web page, and each of whose edges corresponds to a hyperlink from one web page to an...
Let G be the set of finite graphs whose vertices belong to some fixed countable set, and let ≡ be an equivalence relation on G. By the strengthening of ≡ we mean an equivalen...
Fix an element x of a finite partially ordered set P on n elements. Then let hi(x) be the number of linear extensions of P in which x is in position i, counting from the bottom. T...
If X is a geodesic metric space and x1, x2, x3 ∈ X, a geodesic triangle T = {x1, x2, x3} is the union of the three geodesics [x1x2], [x2x3] and [x3x1] in X. The space X is δ-hy...