Identities With Squares of Binomial Coefficients: an Elementary and Explicit Approach


Emrah Kılıç, Helmut Prodinger




In 2014, Slavik presented a recursive method to find closed forms for two kinds of sums involving squares of binomial coefficients. We give an elementary and explicit approach to compute these two kinds of sums. It is based on a triangle of numbers which is akin to the Stirling subset numbers.