All Questions
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Finishing the task to find the solutions of $\frac{1}{x}-\frac{1}{y}=\frac{1}{\varphi(xy)},$ where $\varphi(n)$ denotes the Euler's totient function
In this post I evoke a variant of the equations showed in section D28 A reciprocal diophantine equation from [1], using particular values of the Euler's totient function $\varphi(n)$. I ask it from a ...
user243301
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For which natural numbers are $\phi(n)=2$?
I found this exercise in Beachy and Blair: Abstract algebra:
Find all natural numbers $n$ such that $\varphi(n)=2$, where $\varphi(n)$ means the totient function.
My try:
$\varphi(n)=2$ if $n=3,4,...
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If $a\mid b$ then $\phi(a)\mid \phi(b)$ for $a,b\in\mathbb{N}$ [duplicate]
Hey I would like to show that
$a\mid b\Rightarrow \varphi(a)\mid\varphi(b)\qquad a,b\in\mathbb{N}$
where $\varphi(n)$ is the the totient function.
My try:
Let $a,b\in\mathbb{N}$ and $a\mid b$. ...
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About the divisors of totient numbers
Are there infinitely many integers that do not divide any totient number?
My try:
If $a|b$ then $\phi(a)|\phi(b)$, so the main question would be equivalent to asking wether there are infinitely many ...
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