Enumerating topological (nk)-configurations

Abstract. An (nk)-configuration is a set of n points and n lines in the projec-tive plane such that their point – line incidence graph is k-regular. The configu-ration is geometric, topological, or combinatorial depending on whether lines are considered to be straight lines, pseudolines, or just combinatorial lines. We provide an algorithm for generating, for given n and k, all topological (nk)-configurations up to combinatorial isomorphism, without enumerating first all combinatorial (nk)-configurations. We apply this algorithm to confirm efficiently a former result on topological (184)-configurations, from which we obtain a new geometric (184)-configuration. Preliminary results on (194)-confi-gurations are also briefly reported. 1