Calculating combinations with Duplicates and no Rearangements
116647
The number of different ways to choose $k$ out of $n$ unique items
126025
Computing the inverse of a permutation
24212
proving how many permutations exist.
142477
Closed-form expression for the number of $k$-permutations of length $n$. Duplicates allowed!
149807
Get a list of combinations of lists' elements
104670
Combinations Of String While Maintaining Order Of Words
153174
How can I get every distinct size-n combination of a list?
60661
How to solve this combination problem quickly?
74682
How should I solve combination addition like this?
19101
Permutation induced by a partition
626
Sum of combinations with varying $n$
30575
How to precalculate valid number of combinations instead of using while loop?
12749
How to generate all possible combinations of vectors without caring for order?
98744
How to distinguish between permutation and combination questions?
8049
Generating Combinations
150281
Am I on the right track to figure out this combinatorics problem?
60416
Finding a permutation, and number of, from powers of the permutation