I was reading on the internet about this but I cannot seem to find a proof.
Let f(x)=ax^2 + bx + c be a non-constant polynomial, and assume that a, b, and c are integers.
Prove that there are infinitely many integers n such that f(n) is compsite.
As a hint to the prove, the author noted "Show that there is an integer d such that f(d) has absolute value greater than 1. Let D=f(d), and then show that D divides f(Dj+d) for every integer j."
Any help would be appreciated!