Abstract
We consider a finite class of weighted quadratures with the weight function x(-2a)(1 + x(2))(-)b on (-infinity, infinity), which is valid only for finite values of n (the number of nodes). This means that classical Gauss-Jacobi quadrature rules cannot be considered for this class, because some restrictions such as {maxn} <= a + b - 1/2, a < 1/2, b > 0 and (-1)(2a) = 1 must be satisfied for its orthogonality relation. Some analytic examples are given in this sense.