immediate fact $p/q \cdot b^n$ is a integer
81154
Characterising reals with terminating decimal expansions
62342
$x_1 \cdot \dots \cdot x_n=1 \implies x_1 + \dots + x_n \ge n$
22367
How do I prove that for every positive integer $n$, there exist $n$ consecutive positive integers, each of which is composite?
66272
Is there a common notion of $\mathbb{R}^n$, for non-integer $n$?
54699
Product of pairwise coprime integers divides $b$ if each integer divides $b$
116356
Combinatorial proof of $2 \cdot 3^0 + 2 \cdot 3^1 + 2 \cdot 3^2 + \cdots 2 \cdot 3^{n-1} = 3^n-1$
97684
Show $\frac{(2n)!}{n!\cdot 2^n}$ is an integer for $n$ greater than or equal to $0$
33233
Need to prove that $(S,\cdot)$ defined by the binary operation $a\cdot b = a+b+ab$ is an abelian group on $S = \Bbb R \setminus \{-1\}$.
115866
Proof by induction; $a^n$ divides $b^n$ implies $a$ divides $b$
4750
Show that for any positive integer n, $(3n)!/(3!)^n$ is an integer.
121890
Proof that $ p $ | ${ p^n \choose k } $ for any prime $p$ and $ k < p^n$
98871
How to prove that if a prime divides a Fermat Number then $p=k\cdot 2^{n+2}+1$?
103854
Showing that $Q_n=D_n+D_{n-1}$
150289
A number with an interesting property. $abcd=a^b c^d$
98946
Prove that $(mn)!$ is divisible by $(n!)\cdot(m!)^n$
725
proof of $\sum_{n=1}^\infty n \cdot x^n= \frac{x}{(x-1)^2}$
4512
Is there a direct, elementary proof of $n = \sum_{k|n} \phi(k)$?