In combinatorics, stars and bars (also called "sticks and stones",[1] "balls and bars",[2] and "dots and dividers"[3]) is a graphical aid for deriving certain combinatorial theorems. It can be used to solve many simple counting problems, such as how many ways there are to put n indistinguishable balls into k distinguishable bins.[4]
Theorems one and two are the coefficients used for 2 different support ranges in the negative binomial probability distribution.