Sieving Prime Numbers From Thin Ore
Barry A. Cipra · Science · 1998
Mathematicians have almost always been unable to take an infinite but sparsely distributed set of integers, such as the values of n + 1, and tell how rich in prime numbers it is, but now two mathematicians have developed powerful new techniques for assaying such thin subsets of integers for primes by refining a tool known as the asymptotic sieve. The new sieve shows that even though most numbers of the form a + b are composite--products of prime factors--the sequence includes an infinite number of primes.