Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Sagan numbers   We define a new class of numbers based on the first occurrence of certain
patterns of zeros and ones in the expansion of irracional numbers in a given
basis and call them Sagan numbers, since they were first mentioned, in a
special case, by the North-american astronomer Carl E. Sagan in his
science-fiction novel "Contact." Sagan numbers hold connections with a wealth
of mathematical ideas. We describe some properties of the newly defined numbers
and indicate directions for further amusement.

9
The categories of this paper are: nlin
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat
34
The categories of this paper are: chem-ph
1
The categories of this paper are: cs
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The categories of this paper are: math-ph
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The categories of this paper are: stat
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-ex
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The categories of this paper are: astro-ph
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The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
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The categories of this paper are: bayes-an
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The categories of this paper are: nucl-ex
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The categories of this paper are: chao-dyn