Prime Numbers

I found something interesting that I have not proven, but it has not failed yet: The integer N is prime if: 2^N - 2 --------- N is an integer. Don't ask how I found it, I was just fooling around. Now: Is there some way to reverse the formula so we can insert and integer and get a prime number out? Let me know, I am over excited. _ . _ ___ _ . _ ===-|)/\\/|V|/\/\ (_)/_\|_|\_/(_)/_\|_| Stop by for an excursion into the-=== ===-|)||| | |\/\/ mud.crl.com 8888 (_) Virtual Bay Area! -===