Power subgroups of some Hecke groups

Abstract

Let q > 3 be an even integer and let H(lambda(q)) be the Hecke group associated to q. Let m be a positive integer and H-m(lambda(q)) the power subgroup of H(lambda(q)). In this work the power subgroups H-m(lambda(q)) are discussed. The Reidemeister-Schreier method and the permutation method are used to obtain the abstract group structure and generators of H-m(lambda(q)); their signatures are then also determined.