If we take and let in (1.2.1),
then we obtain the dual Hahn polynomials from the Racah polynomials. So we have
And if we take and let in (1.2.1), then we also obtain the dual Hahn polynomials :
Finally, if we take and in the definition (1.2.1) of the Racah polynomials and take the limit we find the dual Hahn polynomials given by (1.6.1) in the following way :
To obtain the Meixner polynomials from the dual Hahn polynomials we have to take
and in the definition (1.6.1) of
the dual Hahn polynomials and let :
In the same way we find the Krawtchouk polynomials from the dual Hahn polynomials
by setting , in (1.6.1) and let :