Hugo van der Sanden
I am a professional programmer, and a recreational mathematician with particular interest in Number Theory.
13 What's the simplest rational not expressible as a sum of a given number of unit fractions? Sep 14 '10
9 A balls-and-colours problem Oct 13 '10
5 Are there primes p, q such that p^4+1 = 2q^2 ? May 14 '10
2 How to characterize a Self-avoiding path. Oct 10 '10
1 other examples of composition of functions Jun 9 '10