Simple Combinatorial Proof
29828
Combinatorial proof of $\sum^{n}_{i=1}\binom{n}{i}i=n2^{n-1}$.
30136
Proof that a Combination is an integer
82872
Combinatorial proof involving partitions and generating functions
90519
Combinatorial proof of $\sum\limits_{k=0}^n {n \choose k}3^k=4^n$
41205
Help me solve a combinatorial problem
19776
Simplify a combinatorial sum
3786
Help finding a combinatorial proof of $k {n \choose k } = n {n - 1 \choose k -1}\;$
70327
the numer of partial function between two sets in combinatoric way
66019
Revisited: Binomial Theorem: An Inductive Proof
89552
proving combinatorics identity - $\sum_{k=0}^m{n-k \choose m-k}={n+1 \choose m}$
86389
Combinatorial argument to prove the recurrence relation for number of derangements
48434
Prove that $\sum\limits_{k=0}^m\binom{m}k\binom{n}{r+k}=\binom{m+n}{m+r}$ using combinatoric arguments.
111032
Proof of Sets involving the Cartesian Product
39724
Combinatorial Identities
67927
Combinatorial argument for the identity $k\binom{n}{k} = n\binom{n-1}{k-1}$
112573
Combinatorial proof for Stirling number of 1st kind's generating function
146867
Combinatorial Proof Of A Number Theory Theorem--Confusion