Description

This issue is a feature proposal.

As a continuation of #3107, we will add rng for beta negative binomial distribution.

Expected Output

ints beta_neg_binomial_rng(reals r, reals alpha, reals beta)

Checklist

This will require abeta_neg_binomial_lccdf with analytical derivatives.

• rng
• test of rng

Current Version:

v4.9.0