Re: [math-fun] Mapping problem

I'm not feeling particularly patient at the moment. Can you kindly say what the notation "Z(n)" stands for? I can try to guess, of course, but I would rather not. —Dan ----- Let S(n) be the largest subset of Z(n) fixed by the mapping n -> n^2, and let f(n) = |Z(n)|. For example, S(25) = {0, 1, 6, 11, 16, 21} is the largest set of residues modulo 25 fixed by the mapping n -> n^2, so f(25) = |S(25)| = 6. Can you find a formula for f(n) in terms of n? -----