Congruence Subgroups of PSL(2, Z) of Genus Less than or Equal to 24

Abstract

In this paper, we report the computation and tabulation, using MAGMA, of all congruence subgroups of PSL(2, Z) of genus less than or equal to 24. We include full tables of the congruence groups of genus 0, 1, 2, and 3 and a summary of the remaining cases.