7 citations · 15 across the 24 of their papers we have counts for
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Arithmetic and geometry of the Hecke groups
Cheng Lien Lang, Mong Lung Lang
We study the arithmetic and geometry properties of the Hecke group . In particular, we prove that has a subgroup of index , genus with cusps, a…
Commutator subgroup of the Hecke group is not congruence
Cheng Lien Lang, Mong Lung Lang
We prove that the power subgroup and the commutator subgroup of the Hecke group are not congruence.
Wohlfahrt's Theorem for the Hecke group G_5
Cheng Lien Lang, Mong Lung Lang
Let K be a subgroup of the inhomogeneous Hecke group G_5 of finite index. Suppose that the geometric level of K is r. Then K is congruence if and only if K contains the principal c…
The index formula for the Hecke group H_5
Cheng Lien Lang, Mong Lung Lang
The present article gives the index formula of the principal congruence subgroups of the Hecke group H_5
Ranks of the Sylow 2-subgroups of the classical Simple groups
Mong Lung Lang
We determine the ranks of the Sylow 2-subgroups of the classical simple groups of odd characteristic.
Ranks of the Sylow 2-subgroups of the classical groups
Mong Lung Lang
We determine the ranks and normal ranks of the Sylow 2-subgroups of the classical groups of odd characteristic.