1. Introduction
Z.-W. Sun [10,11]proved some divisibility properties of binomial coefficients, such as
Some other divisibility properties on binomial coefficients were obtained by different authors (see, for example, [2,4–6,8]).
Motivated by Sun’s work, we shall prove the following divisibility results on sums of binomial coefficients, the first one confirming a sum divisibility conjectured by Z.-W.Sun