Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

**cooljackiec****Member**- Registered: 2012-12-13
- Posts: 185

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

Offline

**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,015

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

The knowledge of some things as a function of age is a delta function.

Offline

**cooljackiec****Member**- Registered: 2012-12-13
- Posts: 185

how would you prove that? by induction?

I see you have graph paper.

You must be plotting something

Offline

**anonimnystefy****Real Member**- From: Harlan's World
- Registered: 2011-05-23
- Posts: 16,015

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

The knowledge of some things as a function of age is a delta function.

Offline