On prime-generating linear polynomials and x^2+1
  In this paper we use Dirichlet's theorem in order to elementally prove two theorems. The first says that since a polynomial ax+b generates one prime, it also generates infinites. The second theorem (which is proved in a very simillar way to the first) says that x^2+1 generates infinitely many primes. 
Hil\'ario Fernandes
math.GM