set theory ,permutation and combination.
57822
Number of ways to choose two disjoint subsets of a set
68230
The cardinality of a countable union of sets with less than continuum cardinality
68581
Combination for subset with duplicates
18788
Derangements of multisets
23322
Combinatorics Inclusion - Exclusion Principle
1627
Cartesian product of an arbitrary number of sets
126015
Elementary number theory in sets
8049
Generating Combinations
30968
Is it possible that every set can be specified?
158507
Max family of odd subset of a nested set.
95373
Additive set function on a semiring of sets
20722
Fixed points in random permutation
12539
Set Theory: Equivalency of Axiom of Choice and Choice Function
140044
A set union find algorithm
135408
Solving permutation problem sequentially.
133497
Group Membership Test for Permutations
44214
The number of subsets of a set of cardinality $n$