Number of surjective functions from the cardinals of the sets
40566
Counting surjective functions
155168
Is the collection of finite subsets of $\mathbb{Z}$ countable?
117793
Finding a function $\mathbb{N} \to \mathbb{N}$ that is surjective but not injective.
14972
Cardinality of Vitali sets: countably or uncountably infinite?
144787
Show that the set of all infinite subsets of $\mathbb{N}$ has cardinality greater than $\mathbb{N}$
40071
What is the cardinality of the set of all topologies on $\mathbb{R}$?
9651
Cardinality of cartesian product of an infinite set with N
146436
Cardinality of the set of bijective functions on $\mathbb{N}$?
55840
Number of functions from n-element set to {1, 2, …, m}
38286
Proving the Cantor Pairing Function Bijective
149673
Cardinality of an infinite union of finite sets
101669
Cardinality of the Set of all finite subset of $\mathbb{R}$
117862
Number of partitions of an $n$-element set into $k$ classes
65098
Number of $\sigma$  -Algebra on the finite set
82628
Cardinality of a set of closed intervals
23442
Cardinality of the union of infinite and countable sets
79974
The cardinality of Lebesgue sets