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Abstract for 
Dominique Dumont and Armand Ramamonjisoa,
Grammaire de Ramanujan et Arbres de Cayley

We study three sequences of polynomials defined as successive
derivatives with respect to a differential operator
associated with a grammar (one of these sequences
was originally introduced by Ramanujan).
Combinatorial interpretations for these polynomials
are found in terms of rooted trees and graphs of
mappings from $[n]$ to $[n]$.





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