Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On sums of three squares   Let $r_3(n)$ be the number of representations of a positive integer $n$ as a
sum of three squares of integers. We give two distinct proofs of a conjecture
of Wagon concerning the asymptotic value of the mean square of $r_3(n)$.

19
The categories of this paper are: eess
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
13
The categories of this paper are: quant-ph
14
The categories of this paper are: math-ph
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
17
The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th