Totient summatory function
= Totient summatory function
{wiki=Totient_summatory_function}
The Totient summatory function, often denoted as \\( S(n) \\), is a mathematical function that sums the values of the Euler's totient function \\( \\phi(k) \\) for all integers \\( k \\) from 1 to \\( n \\). The Euler’s totient function \\( \\phi(k) \\) counts the number of positive integers up to \\( k \\) that are relatively prime to \\( k \\) (i.e.