• anonymous
Show that if $2^{m}+1$ is prime then $m=2^{n}$ $n \in \mathbb{N}$ Guidance: $m=r*2^{n}$ So I've started like this: $2^{m}+1=2^{r*2^{n}} +1 = \left( 2^{2^{n}} \right)^{r}+1$ I assume that's a somewhat correct beginning but how do I continue?
Mathematics

Looking for something else?

Not the answer you are looking for? Search for more explanations.