Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Three Generalizations of Davenport-Schinzel Sequences   We present new, and mostly sharp, bounds on the maximum length of certain
generalizations of Davenport-Schinzel sequences. Among the results are sharp
bounds on order-$s$ {\em double DS} sequences, for all $s$, sharp bounds on
sequences avoiding {\em catenated permutations} (aka formation free sequences),
and new lower bounds on sequences avoiding {\em zig-zagging} patterns.

13
The categories of this paper are: quant-ph
15
The categories of this paper are: nucl-ex
6
The categories of this paper are: astro-ph
3
The categories of this paper are: physics
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
8
The categories of this paper are: hep-ex
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg