Is there a general formula for $I(m,n)$?
5537
Closed form for $ \int_0^\infty {\frac{{{x^n}}}{{1 + {x^m}}}dx }$
37012
The number of summands $\phi(n)$
30472
Evaluate $\sum_{k=0}^{n} {n \choose k}{m \choose k}$ for a given $n$ and $m$.
46132
Combinatorial interpretation for the identity $\sum\limits_i\binom{m}{i}\binom{n}{j-i}=\binom{m+n}{j}$?
111951
Prove $\binom{n}{m}\binom{m}{k} = \binom{n}{k}\binom{n-k}{m-k}$
107010
How many elements of order $k$ are in $S_n$?
88124
$M,N\in \Bbb R ^{n\times n}$, show that $e^{(M+N)} = e^{M}e^N$ given $MN=NM$
36747
$\text{Tor}_0^R(M,N)\simeq M\otimes_R N$
111779
Ordinary generating function for $\binom{3n}{n}$
57221
counting the number of elements in a conjugacy class of $S_n$
33144
Criterion for $\phi(mn)=m\phi(n)$ to be true
115209
Elementary formula for permutations?
44577
Finding a formula to sum natural numbers up to $n$
26343
Number of certain (0,1)-matrices, Stanley's Enumerative Combinatorics
129920
Is there any formula for number of divisors of $a \times b$?
31555
Divisor of $m$ and $n$ divides $m - qn$ (in proof of Euclidean algorithm)
46065
How do you find all $n$ such that $\phi(n)|n$