Skip to main content
2 of 3
minor typos
Martin Sleziak
  • 4.7k
  • 4
  • 35
  • 40

Prove that $\frac{2^n-2}{n}$ is composite number

If positive integer $n$ such $n\mid2^n-2$,where $n>1$, we called $n$ is Poulet number, see: https://en.wikipedia.org/wiki/Super-Poulet_number

I found if $n$ is Poulet number, then $\dfrac{2^n-2}{n}$ always is composite number

Is this a known result? if $n$ is odd number, so $\frac{2^n-2}{n}$ is even number, and $\frac{2^n-2}{n}>2$,so $\frac{2^n-2}{n}$ is composite number.

But for $n$ is even number. I can't prove it

math110
  • 4.3k
  • 18
  • 46