I first read it a few years back in Excursion's in Number Theory [0]. Super approachable (and short!), I read it in high school with only a little bit of calcul

I first read it a few years back in Excursion's in Number Theory [0]. Super approachable (and short!), I read it in high school with only a little bit of calculus knowledge. [0]: http://www.amazon.com/Excursions-Number-Theory-Dover-Mathematics/dp/0486257789 http://www.amazon.com/Excursions-Number-Theory-Dover-Mathema...