Re: [math-fun] Klein quartic

I just learned from Wikipedia that the article by Noam Elkies in "The Eightfold Way" -- "The Klein quartic in number theory" -- contains a short exposition of a proof (by the mathematician Monsur Kenku) that uses the Klein quartic to demonstrate Heegner's theorem (that was conjectured by Gauss): The only imaginary quadratic number fields Q(sqrt(-n)) such that the corresponding ring of algebraic integers has unique factorization are those for n in {1, 2, 3, 7, 11, 19, 43, 67, 163}. (see p. 93 of the book). Elkies's article uses mathematics that is far beyond my current level of understanding. --Dan Sometimes the brain has a mind of its own.