An arithmetic Le Monde mathematical puzzle: Given an integer k__1, consider the sequence defined by F(1)=1+1 mod k, F²(1)=F(1)+2 mod k, F³(1)=F²(1)+3 mod k, &tc. For which value of k is the sequence the entire {0,1,…,k-1} set? This leads to an easy brute force resolution, for