标签：prime lfloor frac limits sum rfloor 数学题
数学题笔记整理
\[\sum\limits_{p\in prime}\sum\limits_{i=1}^{n}\sum\limits_{j=1}^{n}\gcd(i,j)=p\\
\]
\[\sum\limits_{p\in prime}\sum\limits_{i=1}^{\lfloor\frac{n}{p}\rfloor}\sum\limits_{j=1}^{\lfloor\frac{n}{p}\rfloor}\gcd(i,j)=1\\
\]
\[\sum\limits_{p\in prime}\sum\limits_{i=1}^{\lfloor\frac{n}{p}\rfloor}\left(\sum\limits_{j=1}^i2\times [\gcd(i,j)=1]\right)-1\\
\]
\[\sum\limits_{p\in prime}\sum\limits_{i=1}^{\lfloor\frac{n}{p}\rfloor}\left(\sum\limits_{j=1}^i2\times [\gcd(i,j)=1]\right)-1\\
\]
\[\sum\limits_{p\in prime}\sum\limits_{i=1}^{\lfloor\frac{n}{p}\rfloor}\left(\sum\limits_{j=1}^i2\times \varphi(i)\right)-1\\
\]
标签：prime,
lfloor,
frac,
limits,
sum,
rfloor,
数学题
From： https://www.cnblogs.com/Tyrue-blog/p/17789132.html