Tavakoli, M.; Rahbarnia, F.; Mirzavaziri, M.; Ashrafi, A. R.; Gutman, I. Extremely irregular graphs. (English) Zbl 1299.05060 Kragujevac J. Math. 37, No. 1, 135-139 (2013). Summary: The irregularity of a graph \(G\) is defined as \(\operatorname{irr}(G)=\sum| d(x)-d(y)| \) where \(d(x)\) is the degree of vertex \(x\) and the summation embraces all pairs of adjacent vertices of \(G\). We characterize the graphs minimum and maximum values of \(\operatorname{irr}\). Cited in 7 Documents MSC: 05C07 Vertex degrees 05C05 Trees Keywords:irregularity of graphs; Albertson index; third Zagreb index; degree of vertex PDFBibTeX XMLCite \textit{M. Tavakoli} et al., Kragujevac J. Math. 37, No. 1, 135--139 (2013; Zbl 1299.05060) Online Encyclopedia of Integer Sequences: a(n) = floor(n/3)*(n - floor(n/3))*(n - floor(n/3) - 1).