Proving an expression is an integer (number theory)
12096
If $a+1/a$ is an integer, then so is $a^t+1/a^t$ for $t\in\mathbb N$
152638
The set of integers $n$ expressible as $n=x^2+xy+y^2$
68400
Proof that $\frac{(2n)!}{2^n}$ is integer
108873
How would one be able to prove mathematically that $1+1 = 2$?
156607
Show that $L_p =\frac{1^p+2^p+3^p+...+(p-1)^p}{p}$ is an integer and generalize the integer for all odd integers p
101899
Proof By Induction of a Sum
120309
Number Theory Inequality Proof
56760
Prove by induction that an expression is divisible by 11
83935
Using congruences, show $\frac{1}{5}n^5 + \frac{1}{3}n^3 + \frac{7}{15}n$ is integer for every $n$
140140
An identity which applies to all of the natural numbers
136700
Proving divisibility of expression using induction
102039
If any integer to the power of $x$ is integer, must $x$ be integer?
33104
Combinatorial Proof with Summation Identity
147986
Prove: if $|z|=1$ than $\frac{z+1}{z-1}$ is an imaginary number
136310
Prime number in a polynomial expression
20438
Prove that every positive integer $n$ has a unique expression of the form: $2^{r}m$ where $r\ge 0$ and $m$ is an odd positive integer
46286
Prove if $a\mid b$ and $b\mid a$, then $|a|=|b|$ , $a, b$ are integers.