Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the $r$-shifted central triangles of a Riordan array   Let $A$ be a proper Riordan array with general element $a_{n,k}$. We study
the one parameter family of matrices whose general elements are given by
$a_{2n+r, n+k+r}$. We show that each such matrix can be factored into a product
of a Riordan array and the original Riordan array $A$, thus exhibiting each
element of the family as a Riordan array. We find transition relations between
the elements of the family, and examples are given. Lagrange inversion is used
as a main tool in the proof of these results.

36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
3
The categories of this paper are: physics
33
The categories of this paper are: plasm-ph