In this note we give a simple proof of a result of Richter and Siran by basic counting method, which says that the crossing number of $K_{3,n}$ in a surface with Euler genus ε is ⎣n/(2ε+2)⎦ {n - (ε+1)(1+⎣n/(2ε+2)⎦)}.
Department of Mathematics, MATH 1044, Purdue University, West Lafayette, IN 47907-2067, USA
Bibliografia
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