Bijection between $N$ and $Q $
5803
Produce an explicit bijection between rationals and naturals?
37951
proof detail concerning bijection between a set and its power set
72642
Continuous bijection from $(a,b) \to S^1$?
18343
Counting homomorphisms between $\Bbb Z$ and $\Bbb Z_n$ and also between $\Bbb Z_n$ and $\Bbb Q$
13453
Bijection map from a set of subgroup to another set of subgroup under some condition.
39642
Efficient way to find $[\mathbb{Q}(\sqrt{5}, \sqrt{3}, \sqrt{2}): \mathbb{Q}(\sqrt{3}, \sqrt{2})]$
78847
Bijection between Prime numbers and Natural numbers
52348
Counting the number of surjections.
98518
Cardinality of equivalence relations on N
141114
Question about a bijection between $\mathbb R$ and $\mathbb R \cup \{\infty\}$
67644
How does one get the formula for this bijection from $\mathbb{N}\times\mathbb{N}$ onto $\mathbb{N}$?
141984
Find the number of homomorphisms between $\mathbb{Z}_m$ and $\mathbb{Z}_n$
104274
Express $C$ interms of the sets $A_n$
157268
Proving a bijection with absolute value
50649
On the existence of a continuous bijection $f\colon [0,1]\to [0,1]\times [0,1]$
72591
Find a bijection to prove a fact about integer partitions
21707
Constructing a Bijective function via an injective and surjective one.