Some Double Sums Involving Ratios of Binomial Coefficients Arising From Urn Models

David Stenlund, James G. Wan

In this paper we discuss a class of double sums involving ratios of binomial coefficients. The sums are of the form \[ \sum_{j=0}^{n} \sum_{i=0}^j \frac{\binom{f_1(n)}{i}}{\binom{f…