Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Bijections for refined restricted permutations   We present a bijection between 321- and 132-avoiding permutations that
preserves the number of fixed points and the number of excedances. This gives a
simple combinatorial proof of recent results of Robertson, Saracino and
Zeilberger, and the first author. We also show that our bijection preserves
additional statistics, which extends the previous results.

17
The categories of this paper are: q-fin
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
0
The categories of this paper are: hep-ph
1
The categories of this paper are: cs
28
The categories of this paper are: alg-geom
10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
35
The categories of this paper are: mtrl-th