I was stuck by a combinatoric question. Can someone give me a hint?
132921
Counting problem, number of moves
65307
Simple combination/probability question based on string-length and possible-characters
139039
Stars and Bars Combinatorics Problem
156383
Proving a combinatorial identity without double counting
93459
Number of permutations of unspecified length
82872
Combinatorial proof involving partitions and generating functions
72052
Combinatorics the number of options for $k$ different balls in n different cells, with at least $1$ ball in each cell
21000
Calculating $\sum_{k=1}^nk(k!)$ combinatorially
19776
Simplify a combinatorial sum
27141
Combinatorics identity question
140806
How do I tackle this combinatorics problem about married couples around a table?
41008
how many permutations of {1,2,...,9}
104268
Confusion on how to solve this question about sequences.
13860
IMO/1981 - Combinatorics
144025
Number of Solutions in this Number Puzzle
65843
Number of possible combinations of x numbers that sum to y
136449
Combinatorics problem on $20$ people, $12$ months, and distinguishable groups