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**cooljackiec****Member**- Registered: 2012-12-13
- Posts: 160

could someone give me a step by step solution. I figured out

was which are odd numbers. I am not sure if i could do the same to this and divide it by 3.*Last edited by cooljackiec (2013-10-08 12:40:28)*

I see you have graph paper.

You must be plotting something

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**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,507

Hi

The answer is 2*3^99, like you thought it might be. For all primes p it is true that phi(p^n)=p^n-p^(n-1).

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

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**cooljackiec****Member**- Registered: 2012-12-13
- Posts: 160

how would you prove that? by induction?

I see you have graph paper.

You must be plotting something

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**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,507

Not exactly. I'd prove it using your idea. 1/p of the first p^n nunbers are not relatively prime to p^n and the rest is, so phi(p^n)=p^n-(1/p)*p^n=p^n-p^(n-1).

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

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