Symbols:Greek/Sigma/Divisor Sum Function

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Divisor Sum Function

$\map {\sigma_1} n$


Let $n$ be an integer such that $n \ge 1$.

The divisor sum function $\map {\sigma_1} n$ is defined on $n$ as being the sum of all the positive integer divisors of $n$.

That is:

$\ds \map {\sigma_1} n = \sum_{d \mathop \divides n} d$

where $\ds \sum_{d \mathop \divides n}$ is the sum over all divisors of $n$.


The $\LaTeX$ code for \(\map {\sigma_1} n\) is \map {\sigma_1} n .


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