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Combinatorics of Riordan arrays with identical $$A$$ and $$Z$$ sequences. (English) Zbl 1243.05007
Summary: In theory, Riordan arrays can have any A-sequence and any Z-sequence. For examples of combinatorial interest they tend to be related. Here we look at the case that they are identical or nearly so. We provide a combinatorial interpretation in terms of weighted Łukasiewicz paths and then look at several large classes of examples.

##### MSC:
 05A05 Permutations, words, matrices 05A15 Exact enumeration problems, generating functions
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