Is there a general way to count the number of sigma-algebras on a finite set?
65098
Number of $\sigma$  -Algebra on the finite set
117133
Is there an infinite countable $\sigma$-algebra on an uncountable set
55157
$\sigma$-algebras on a countable set is generated by partitions of the set
68512
$\sigma$ algebra of collection of random variables
84132
Number of preimages of a group element under a homomorphism.
16048
Approximating a $\sigma$-algebra by a generating algebra
120273
Showing that a collection of sets is a $\sigma$-algebra: either set or complement is countable
38946
Show that $\{\cup_{n\in K} (n, n+1]: K \subset \mathbb{Z}\}$ is a $\sigma$-algebra on $\mathbb{R}$
19996
Example where union of increasing sigma algebras is not a sigma algebra
139826
arbitrary large finite sums of an uncountable set.
154474
Image of countable and uncountable sets
63860
Measure of Dependence Between Two $\sigma$-algebras
103769
The Cartesian product of a finite number of countable sets is countable
53642
Cardinality of Borel sigma algebra
134983
Borel sigma algebra not containing all subsets of $\mathbb{R}$?
123847
Cardinality of $GL_n(K)$ when $K$ is finite
14861
If $\sigma\in S_n$ is of length $n$, then $\sigma$ generates its centralizer