$2^r-1$ divides $2^{rs}-1$
1448
$x^a - 1$ divides $x^b - 1$ if and only if $a$ divides $b$
73025
Find min natural number $n$ so that $2^{2002}$ divides $2001^{n}-1$
114198
Showing that $y$ is irreducible in $\mathbb R[x,y]/(x^2+y^2-1)$.
72511
If $n$ is an odd natural number, then $8$ divides $n^{2}-1$
153302
$9$ divides $n-r(n)$ where $r(n)$ is $n$ with its digits reversed
35553
If $n$ is composite, so is $2^n-1$
112631
Prove that if $d$ divides $n$, then $2^d -1$ divides $2^n -1$
5043
Show that $2^n>1+n\sqrt{2^{n-1}}$
107765
Prove that there exists two roots in $[-1,1]$
156956
Give the remainder of $x^{100}$ divided by $(x-2)(x-1)$.
142347
What is the highest power of $n$ in $(n^r-1)!$
34059
$(a^{2^n}+1,a^{2^m}+1)=1 or 2$
102316
why $(r+I)(s+I) = rs + I$ in the quotient ring $R ?$
22093
How to show $a^{2^n}+1 \mid a^{2^m}-1$?
81890
What does $2^{\mathbb R}$ mean?
37525
Maximum power of $2$ which divides $3^{1024}-1$
107848
Finding the remainder of $\overbrace{11\ldots1}^{123 \text{ times}}$ divided by $271$