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[数论] 存在$m$使得$n\mid(2^m+m)$

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abababa posted 2021-2-21 18:07 |Read mode
对任意的正整数$n$都存在$m$,使得$n\mid(2^m+m)$。

原帖在 artofproblemsolving.com/community/c6h154177p13659247

里面提到一个用中国剩余定理的方法,但我没理解,请教这是怎么归纳的?
根据中国剩余定理,关于$m$的方程组
\[
\begin{cases}
m \equiv m_0 \pmod{\varphi(n)}\\
m \equiv -2^{m_0} \pmod{n}
\end{cases}
\]
有解的充要条件是$\gcd(n,\varphi(n))\mid(m_0+2^{m_0})$

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tommywong posted 2021-2-21 20:15
$m|(x-a),~n|(x-b)$
$(m,n)|(x-a),~(m,n)|(x-b)$
$(m,n)|(a-b)$

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original poster abababa posted 2021-2-21 22:23
回复 2# tommywong

中国剩余定理的那个定理我明白,我是不明白这帖里是怎么用这个定理证明原问题的,主要是不明白怎么归纳的,归纳起步应该是$n=1$时命题成立,但归纳假设是什么?

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tommywong posted 2021-2-22 09:20
回复 3# abababa

佢可能講緊樓上#31個證明

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