If Δr=∣∣ ∣ ∣ ∣ ∣ ∣ ∣ ∣∣2r−11r(r+1)sinnθxyz2n−1nn+1sinn+12θsinn2θsinθ2∣∣ ∣ ∣ ∣ ∣ ∣ ∣ ∣∣, then ∑nr=1Δr is equal to