Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Generalization of the Ramanujan Polynomials and Plane Trees   Generalizing a sequence of Lambert, Cayley and Ramanujan, Chapoton has
recently introduced a polynomial sequence Q_n:=Q_n(x,y,z,t) defined by Q_1=1,
Q_{n+1}=[x+nz+(y+t)(n+y\partial_y)]Q_n. In this paper we prove Chapoton's
conjecture on the duality formula: Q_n(x,y,z,t)=Q_n(x+nz+nt,y,-t,-z), and
answer his question about the combinatorial interpretation of Q_n. Actually we
give combinatorial interpretations of these polynomials in terms of plane
trees, half-mobile trees, and forests of plane trees. Our approach also leads
to a general formula that unifies several known results for enumerating trees
and plane trees.

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The categories of this paper are: q-alg
1
The categories of this paper are: cs
21
The categories of this paper are: adap-org
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The categories of this paper are: q-fin
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The categories of this paper are: funct-an
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The categories of this paper are: solv-int
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The categories of this paper are: ao-sci
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The categories of this paper are: gr-qc
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The categories of this paper are: cmp-lg
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The categories of this paper are: dg-ga
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The categories of this paper are: bayes-an
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The categories of this paper are: plasm-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: physics
0
The categories of this paper are: hep-ph
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The categories of this paper are: hep-ex