Combinatorics problem on $k$ sets and partionning a set of numbers
128552
Remove any number and the remaining numbers can be partitioned into two subsets of equal sum; prove all numbers are equal.
85023
Permutation of n objects with restriction of adjacent pairs
34334
Combinatorics Problem with symbols and spaces
70282
Help finding a combinatorial proof of $k {n \choose k } = n {n - 1 \choose k -1}$
82872
Combinatorial proof involving partitions and generating functions
23322
Combinatorics Inclusion - Exclusion Principle
25769
Finding all posets on a set
117658
A set with n elements has 2^n subsets
74730
Combinatorial Proof of ${{n}\choose{k}} {{k}\choose{j}} = {{n}\choose{j}} {{n-j}\choose{k-j}}$
152911
Stirling numbers combinatorial proof
44214
The number of subsets of a set of cardinality $n$
75804
Is this permutation-sum problem NP-complete?
140416
Catalan number - combinatoric
152333
A problem based on pigeonhole
76635
Proof through combinatorial argument
98082
Another combinatorics problem: $\sum\limits_{k = 0}^n (-1)^k \binom{2n-k}k2^{2n-2k}=2n+1$
20973
How can I find all the subsets of a set, with exactly n elements?