$\frac{1}{5}n^5+\frac{1}{3}n^3+\frac{7}{15}n$ is an integer for every integer n.
83935
Using congruences, show $\frac{1}{5}n^5 + \frac{1}{3}n^3 + \frac{7}{15}n$ is integer for every $n$
14815
How prove this $\prod_{1\le i<j\le n}\frac{a_{j}-a_{i}}{j-i}$ is integer
49372
$x+1/x$ an integer implies $x^n+1/x^n$ an integer
51520
Prove that the only prime triple is 3, 5, 7
21476
Modular Exponentiation 3^5^7
57959
Every $n > 17$ is a non-negative integer combination of $4$ and $7$.
112907
Math Induction Proof: $(1+\frac1n)^n < n$
115733
Proving that $\sec\frac{\pi}{11}\sec\frac{2\pi}{11}\sec\frac{3\pi}{11}\sec\frac{4\pi}{11}\sec\frac{5\pi}{11}=32$
87843
Combinatorial proof that $\frac{({10!})!}{{10!}^{9!}}$ is an integer
33786
Proof that a certain fraction is always an integer
151153
Prove $\frac{a(a^2+2)}{3}$ is an integer for all integer $a\geqslant 1$
85959
How do I prove that among any $5$ integers, you are able to find $3$ such that their sum is divisible by $3$?
32316
Are all integers fractions?
48685
What five odd integers have a sum of $30$?
156356
Proof that $x^n+\frac{1}{x^n}\in \mathbb Z$ by complete induction
39716
Prove that $8(5)^n + 6(3)^{2n} - 80n - 14$ is divisible by $512$ for all $n \in \mathbb{N}$ by induction.
101708
Integers can be expressed as $a^3+b^3+c^3-3abc$