Fundamental Group of complement of Integers
11000
Fundamental group of $\mathbb{R}^2 \setminus (\mathbb{Z} \times \{0\})$
117744
$p$-Sylow in quotient groups
85106
Group of order 10 has an element of order 5, without using Cauchy's or Sylow's theorems
64408
Subgroup of $\mathbb{Q}$ with finite index
19289
complement of a set and its measure
24561
$\mathbb S_n$ as semidirect product
94215
Fundamental group of the connected sum of manifolds
31252
"Efficient version" of Cayley's Theorem in Group Theory
122698
Construction of multiplicative group of complex numbers
131519
intuition on the fundamental group of $S^1$
85222
Direct sum of finitely-many non-abelian groups
41688
An elementary problem in Group Theory: the unique noncyclic group of order 4
5741
Direct product of abelian groups
149750
Help understanding Fundamental Theorem of Finite Abelian Groups
64021
Fundamental group of a torus with points removed
93703
Groups of units of $\mathbb{Z}\left[\frac{1+\sqrt{-3}}{2}\right]$
89215
How to describe the quotient group $\mathbb{Z} \times \mathbb{Z} / \langle (1, 2) \rangle$