Group with exactly two subgroups
128300
Prove that a group with exactly two proper nontrivial subgroups is isomorphic to $\mathbb{Z}_{pq}$ or $\mathbb{Z}_{p^3}$.
92750
Groups where all elements are order 3
25421
Simple or not simple Groups
94999
A subgroup with an index of 2 is normal to the group.
933
How many groups exist with order $n$ (two isomorphic groups are treated as the same group)
14301
Union of subgroups is a subgroup if and only if one subgroup is a subset of the other
122266
equivalent definition of normal subgroup
153797
Is a quotient group a subgroup?
10602
Monotone Union of subgroups being subgroup
156463
The complement of a proper subgroup generates the whole group
91774
Existence of group $G$ with $|G|>2$ and automorphism group of odd order
118030
Two subgroups of the same index must be conjugate under these assumptions
154398
Show that H is a subgroup of G
109060
Group containing no subgroup of index 2
71245
$2 \times 2 $ Orthogonal Group
117324
How to find all subgroups of a group in GAP
87766
Using Cayley's Theorem to find an isomorphic subgroup.