Euler’s totient function \(\phi\colon\ZZ_{\geq 1}\to\ZZ_{\geq 1}\) is \[ \phi(n) \coloneqq \size \theset{ k\in\ZZ \st 1\leq k\leq n,\ \gcd(k ,n ) = 1}. \]
Euler's totient function
D-JX3YC
D-JX3YC
Euler’s totient function \(\phi\colon\ZZ_{\geq 1}\to\ZZ_{\geq 1}\) is \[ \phi(n) \coloneqq \size \theset{ k\in\ZZ \st 1\leq k\leq n,\ \gcd(k ,n ) = 1}. \]