We show that the power subgroups \(M^{6k}\) (\(k > 1\)) of the Modular group \(M = \text{PSL}(2, \mathbb{Z})\) are subgroups of the groups \(M'(6k, 6k)\). Here, the groups \(M'(6k, 6k)\) (\(k > 1\)) are subgroups of the commutator subgroup \(M’\) of \(M\) of index \(36k^2\) in \(M’\).
Citation
Nihal Yilmaz Ozgur. On The Power Subgroups of The Modular Group[J], Ars Combinatoria, Volume 090. 205-208. .