Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Characteristic Function for the Primes   I develop a function that, for any integer $n \geq 2$, takes a value of 1 if
$n$ is prime, 0 if $n$ is composite. I also discuss two applications: First,
the characteristic function provides a new expression for the prime counting
function. Second, the components of the characteristic function point to a new
expression that gives the number of distinct prime factors for any integer
greater than one.

30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
28
The categories of this paper are: alg-geom
1
The categories of this paper are: cs
26
The categories of this paper are: bayes-an
0
The categories of this paper are: hep-ph
31
The categories of this paper are: ao-sci
6
The categories of this paper are: astro-ph
21
The categories of this paper are: adap-org
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex