In my book U(n) is defined as all numbers less than n that are relatively prime to n. U(n) is cyclic for some n but not for all. I was wondering if there is theory behind how to tell if U(n) will be cyclic or, even better, what elements of U(n) generate U(n). Also, the formal name of this group would help a lot too, if anyone knows what it is...(adsbygoogle = window.adsbygoogle || []).push({});

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# How to tell if U(n) is cyclic?

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