Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Five subsets of permutations enumerated as weak sorting permutations   We show that the number of members of S_n avoiding any one of five specific
triples of 4-letter patterns is given by sequence A111279 in OEIS, which is
known to count weak sorting permutations. By numerical evidence, there are no
other (non-trivial) triples of 4-letter patterns giving rise to this sequence.
We make use of a variety of methods in proving our result, including
recurrences, the kernel method, direct counting, and bijections.

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
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
37
The categories of this paper are: supr-con
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The categories of this paper are: astro-ph
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The categories of this paper are: nlin
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The categories of this paper are: patt-sol
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The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
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The categories of this paper are: dg-ga
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The categories of this paper are: plasm-ph
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The categories of this paper are: cmp-lg