  The contribution of Jacques Raynal to angular-momentum theory is highly
valuable. In the present article, I intend to recall the main aspects of his
work related to Wigner $3j$ symbols. It is well known that the latter can be
expressed with a hypergeometric series. The polynomial zeros of the $3j$
coefficients were initially characterized by the number of terms of the series
minus one, which is the degree of the coefficient. A detailed study of the
zeros of the $3j$ coefficient with respect to the degree $n$ for $J = a + b + c
\leq 240$ ($a$, $b$ and $c$ being the angular momenta in the first line of the
$3j$ symbol) by Raynal revealed that most zeros of high degree had small
magnetic quantum numbers. This led him to define the order $m$ to improve the
classification of the zeros of the $3j$ coefficient. Raynal did a search for
the polynomial zeros of degree 1 to 7 and found that the number of zeros of
degree 1 and 2 are infinite, though the number of zeros of degree larger than 3
decreases very quickly as the degree increases. Based on Whipple's
transformations of hypergeometric $_3F_2$ functions with unit argument, Raynal
generalized the Wigner $3j$ symbols to any arguments and pointed out that there
are twelve sets of ten formulas (twelve sets of 120 generalized $3j$ symbols)
which are equivalent in the usual case. In this paper, we also discuss other
aspects of the zeros of $3j$ coefficients, such as the role of Diophantine
equations and powerful numbers, or the alternative approach involving Labarthe
patterns.
