(Oral Mines-Ponts) Pour {n\in\mathbb{N}^*}, on pose {\begin{cases}\sigma(3n)=4 n\\\sigma(3n-1)=2n-1\\\sigma(3 n-2)=4n-2\end{cases}}
|
(Oral Mines-Ponts) Pour {n\in\mathbb{N}^*}, on pose {\begin{cases}\sigma(3n)=4 n\\\sigma(3n-1)=2n-1\\\sigma(3 n-2)=4n-2\end{cases}}
|