Values of $n$ and $r$ for which $ n \choose r$ is defined
128093
Regarding the values that n and r can take in $\binom{n}{r}$
69166
Cardinality of $\mathbb{R}$ and $\mathbb{R}^2$
72567
Does a set of $n$ independent vectors in $R^{n}$ always span $R^{n}$?
77128
Necessary and Sufficient conditions for $(i \, j)$ and $(1 \, 2 \, \dotsc \, n)$ generate $S_n$.
1125
Inductive proof that ${2n\choose n}=\sum{n\choose i}^2.$
104274
Express $C$ interms of the sets $A_n$
94295
Pigeonhole-principle with two choices
56728
Question about limit points of a Subset of $\mathbb{R}$
116913
Whats the difference between the following? $n+k-1 \choose k$ ${{n+k-1}\choose{k-1}}$ ${{n+k-1}\choose{n}}$
142534
Proof of $k {n\choose k} = n {n-1 \choose k-1}$ using direct proof
107010
How many elements of order $k$ are in $S_n$?
70282
Help finding a combinatorial proof of $k {n \choose k } = n {n - 1 \choose k -1}$
76381
Plain integer partitions of $n$ using $r$ parts
30472
Evaluate $\sum_{k=0}^{n} {n \choose k}{m \choose k}$ for a given $n$ and $m$.
91947
Proof of $ f:I_n \rightarrow I_m \Rightarrow n = m$
4552
Choice of $q$ in Baby Rudin's Example 1.1
70301
$\sin(n)$ subsequence limits set