Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Solutions of the problem of Erd\"os-Sierpi\'nski:
  $\sigma(n)=\sigma(n+1)$   For $n\leq 1.5 \cdot 10^{10}$, we have found a total number of 1268 solutions
to the Erd\"os-Sierpi\'nski problem finding positive integer solutions of
$\sigma(n)=\sigma(n+1)$, where $\sigma(n)$ is the sum of the positive divisors
of n. On the basis of that set of solutions the following empirical properties
are enunciated: first, all the $\sigma(n)$, $n$ being a solution, are divisible
by 6; second, the repetition of solutions leads to the formulation of a new
problem: \emph{Find the natural numbers $n$ such that
$\sigma(n)=\sigma(n+1)=\sigma(n+k)=\sigma(n+k+1)$ for some positive integer
$k$}. A third empirical property concerns the asymptotic behavior of the
function of $n$ that gives the number of solutions for $m$ less or equal to
$n$, which we find to be as $n^{1/3}$. Finally some theorems related to the
Erd\"os-Sierpi\'nski problem are enunciated and proved.

29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
20
The categories of this paper are: acc-phys
1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
21
The categories of this paper are: adap-org
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
4
The categories of this paper are: cond-mat