The statement is: "Let n be an odd integer. Show that there is an integer k such that n^2 = 8k + 1."
I'm not sure where to begin. I'm thinking that this statement would be equivalent to saying "n is an odd integer iff there is an integer k such that n^2 = 8k + 1." The only other choice is Proof by Cases (based on the section of the book it is in). Once I know where to start, I'm pretty sure I can do the proof, it's just getting started that is my problem.