Is 2^n + 1 = k^2 only valid when n = k = 3?
43048
When is $2^n \pm 1$ a perfect power
1258
Prove $3^n = \sum_{k=0}^n \binom {n} {k} 2^k$
23406
How do I convince someone that $1+1=2$ may not necessarily be true?
106562
Is $3 \ge 1$ or is it just $3 > 1$?
23301
There does not exist any integer $m$ such that $3n^2+3n+7=m^3$
82636
Maybe is right $\frac{n^2 + 1}{4k + 3} \notin \mathbb{Z}, n, k \in \mathbb{N}^{+}$
149716
Prove that $ \sqrt{n(n+1)(n+2)(n+3)+1} $ is always a natural number
34097
Is it possible that $n^2+1$ has some divisor of the form $4k+3$?
122005
Can $n(n+1)2^{n-2} = \sum_{i=1}^{n} i^2 \binom{n}{i}$ be derived from the binomial theorem?
35504
The Diophantine equation $x^2 + 2 = y^3$
137967
Are there $a,b \in \mathbb{N}$ that ${(\sum_{k=1}^n k)}^a = \sum_{k=1}^n k^b $ beside $2,3$
23638
$a^2b^2+a^2c^2+b^2c^2\leq 3$
69943
why is ${n+1\choose k} = {n\choose k} + {n\choose k-1}$?
134365
When is this true: If $m^2$ is a multiple of N then m is a multiple of N
32760
Is $\mathbf{Q}(\sqrt{2}, \sqrt{3}) = \mathbf{Q}(\sqrt{2}+\sqrt{3})$?
144132
The number $2^{3^n}+1$ is divisible by $3^{n+1}$ and not divisible by $3^{n+2}$.
125618
Prove $2^{3^n}+1 $ is a multiple of $3^{n+1}$ by induction