Find n with this condition
32641
Is there a formula to calculate the sum of all proper divisors of a number?
104965
Find $n$ such that polynomial is divisible
98443
Find positive integers such that $2n^3 + 5|n^4 +n+1$
126288
Find the Set With Given Condition
115719
Find the possible values of |A + B + C |
83149
Factorial Inequality problem $\left(\frac n2\right)^n > n! > \left(\frac n3\right)^n$
57644
Lower bounds for ${{2n} \choose {n}}$
58144
Solve the recurrence relation:$ T(n) = \sqrt{n} T \left(\sqrt n \right) + n$
69791
How to solve: T(n) = T(n - 1) + n
115258
Find all positive integers $n$ such that $\phi(n)+\sigma(n)=2n$.
50781
$(n+1)$th prime $p_{n+1}$ less than or equal to $p_1p_2\dots p_n+1$
13418
Solve the recurrence
138601
There are $2n+1$ people. For each $n$ people there is somebody who is friend with each of them. Prove there is a "know-them-all" person.
148906
Finding integers $m,n$ such that $(m-n)^2=4mn/(m+n-1)$
93572
How to determine if $n (n \geq 2)$ given numbers can be summed up to a certain number?
144017
How to find the smallest $n$ such that $n^a\equiv 1 \pmod p$
80744
What is the number of strings at size $n$ that is constructed from ${a,b,c,d}$ and there is an even num of $a$