Herzberg, Agnes M.; Murty, M. Ram Sudoku squares and chromatic polynomials. (English) Zbl 1177.05022 Int. Math. Nachr., Wien 206, 1-19 (2007). The authors recall the notions of \(\lambda\)-coloring, proper coloring and chromatic number of a graph and introduce so-called Sudoku graph to address the Sudoku puzzles. It is proved that the Sudoku graph of rank \(n\) has chromatic number \(n^2\). Some results on the number of the solutions and the number of Sudoku squares are obtained as well. Reviewer: Peter Boyvalenkov (Sofia) MSC: 05B30 Other designs, configurations 05C15 Coloring of graphs and hypergraphs Keywords:lambda coloring; proper coloring; chromatic number; Sudoku graph; chromatic polynomials PDFBibTeX XMLCite \textit{A. M. Herzberg} and \textit{M. R. Murty}, Int. Math. Nachr., Wien 206, 1--19 (2007; Zbl 1177.05022)