How do we find the 26 topologies on the set X = {a,b,c}
114370
I want to figure out how many Topologies are in the set X
101669
Cardinality of the Set of all finite subset of $\mathbb{R}$
91485
Finding an uncountable chain of subsets the integers
132605
Finding the number of subsets of a set such that an element divides the succeeding element.
46408
Show that the Hausdorff topology is unique in a finite set $X$
152465
Find the intersection of all $T_2$ topologies on an infinite set $X$
108226
Are these bases for a topology?
82207
Number of Pairs of Subsets
95747
Number of countable subsets of $\mathbb{R}$
79974
The cardinality of Lebesgue sets
18343
Counting homomorphisms between $\Bbb Z$ and $\Bbb Z_n$ and also between $\Bbb Z_n$ and $\Bbb Q$
66239
Verifying that a certain collection of intervals of $\mathbb R$ forms a topology
88301
What are all of the connected subsets of $\mathbb{Q}$?
16553
Cardinality of the set of all total orders on $\Bbb{N}$
112050
Union of ascending chain of Topologies
92340
How many metrics are there on a set up to topological equivalence?
70761
Number of ways to connect sets of $k$ dots in a perfect $n$-gon