Applications of stuffle product of multiple zeta values

We obtain some formulas for the stuffle product and apply them to derive a decomposition formula for multiple zeta values. Moreover, we give an application to combinatorics and get the following identity:D(n+1,t+1)+D(n,t)=2∑ℓ=0nD(t,n−ℓ)+2∑ℓ=0tD(n,t−ℓ), where D(n,t) is the Delannoy number.