Divisors of all values of polynomial over $\Bbb Z\,$ (fixed divisors) Very nice example! I went and read up on turbo coding and eventually ended up at spectrum.ieee.org/computing/software/… -- super interesting. I've got your paper on my to-do list as well. :) Thanks for the help. BTW: I sent this on to a friend at work who had just asked me about how this (number theory) was useful. He was really impressed with this application.