  In this paper we review the properties of families of numbers of the form
$6n\pm1$, with $n$ integer (in which there are all prime numbers greater than 3
and other compound numbers with particular properties) to later use them in a
new sieve that allows the separation of numbers $n$ that generate primes from
those that only generate compounds. In principle, this can be used to find the
amount of prime numbers up to a given number $h$; this means, $\pi(h)$.
