Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: An elementary sieve   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, $\pi(h)$.

25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
16
The categories of this paper are: stat
0
The categories of this paper are: hep-ph
4
The categories of this paper are: cond-mat
30
The categories of this paper are: q-alg
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The categories of this paper are: eess
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
22
The categories of this paper are: chao-dyn
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin