Newbetuts

$\frac{a^{2}-1}{b+1}+\frac{b^{2}-1}{a+1}$ an integer $\Rightarrow \frac{a^{2}-1}{b+1}$ and $\frac{b^{2}-1}{a+1}$ are integers. [duplicate]

Finding all functions $f: \mathbb{Z^{+}}\to \mathbb{Z^{+}}$ such that $f(a)| (f(b)+a-b)$ for all $a,b\in \mathbb{Z^{+}}$

Pell number factorization and divisibility question

Generating numbers by repeated doubling and digit reversal

Find the sum of reciprocals of divisors given the sum of divisors

Smallest positive integer that is not coprime to any member of a set of integers

Prove that $\gcd(a^2, b^2) = \gcd(a, b)^2$ [duplicate]

What remainder does $34!$ leave when divided by $71$?

Prove the following (algebra of polynomials)

Prove Divisibility In Fibonacci Sequence Over A Prime Number

Can exist an even number greater than $36$ with more even divisors than $36$, all of them being a prime$-1$?

Is the notation for '$a$ divides $b$' standard?

Prove $6 \nmid [\left( \sqrt[3]{28} - 3 \right)^{-n}]$

Is there a fast divisibility check for a fixed divisor?

Proving gcd($a,b$)lcm($a,b$) = $|ab|$

Prove that $6$ divides $n^3+11n$?

How do you find "good" rational approximations to a decimal number?

New posts in divisibility

Show that $A[X]/(aX+b)$ is an integral domain

Strange inequality in an NT problem

Prove $10^{10^{10^n}} + 10^{10^n} + 10^{n} - 1$ is never prime

$\frac{a^{2}-1}{b+1}+\frac{b^{2}-1}{a+1}$ an integer $\Rightarrow \frac{a^{2}-1}{b+1}$ and $\frac{b^{2}-1}{a+1}$ are integers. [duplicate]

Finding all functions $f: \mathbb{Z^{+}}\to \mathbb{Z^{+}}$ such that $f(a)| (f(b)+a-b)$ for all $a,b\in \mathbb{Z^{+}}$

Pell number factorization and divisibility question

Generating numbers by repeated doubling and digit reversal

Find the sum of reciprocals of divisors given the sum of divisors

Smallest positive integer that is not coprime to any member of a set of integers

Prove that $\gcd(a^2, b^2) = \gcd(a, b)^2$ [duplicate]

What remainder does $34!$ leave when divided by $71$?

Prove the following (algebra of polynomials)

Prove Divisibility In Fibonacci Sequence Over A Prime Number

Can exist an even number greater than $36$ with more even divisors than $36$, all of them being a prime$-1$?

Is the notation for '$a$ divides $b$' standard?

Prove $6 \nmid [\left( \sqrt[3]{28} - 3 \right)^{-n}]$

Is there a fast divisibility check for a fixed divisor?

Proving gcd($a,b$)lcm($a,b$) = $|ab|$

Prove that $6$ divides $n^3+11n$?

How do you find "good" rational approximations to a decimal number?