Let \omega=\cos \frac{2 \pi}{7}+i \cdot \sin \frac{2 \pi}{7}, where i=\sqrt{-1}. Find the value of the product
\prod_{k=0}^{6}\left(\omega^{3 k}+\omega^{k}+1\right)
Let \omega=\cos \frac{2 \pi}{7}+i \cdot \sin \frac{2 \pi}{7}, where i=\sqrt{-1}. Find the value of the product