New posts in Gcd And Lcm

On division by gcd

Why does the Euclidean algorithm for finding GCD work?

What is GCD of $7^{3001}-1$ and $7^{3000}+1$?

How would you prove if $ab|(a+b)(a+b+1)$, then $(a,b) \leq \sqrt{a+b}$ for positive integers $a$ and $b$?

Find the greatest common divisor of $2^m+1$ and $2^n+1$ that $m,n$ are positive integers.

Pairs of integer pairs with same lcm, gcd and mean

Greatest common divisor proof attempt

Probability of a fraction $a/b$ that cannot be simplified

About the limit $\lim_{n \to +\infty} \frac{1}{n^2} \sum_{1 \le a,b \le n} \frac{1}{ \mathrm{gcd} (a,b)} $

Prove that a cyclic group with only one generator can have at most 2 elements