Question Number 211374 by York12 last updated on 07/Sep/24
$$\mathrm{Evaluate}:\:\underset{{k}=\mathrm{1}} {\overset{{n}} {\sum}}\left(\frac{\mathrm{sin}\:\left(\mathrm{2}^{{k}+\mathrm{4}} \theta\right)}{\mathrm{sin}\:\left(\mathrm{2}^{\mathrm{k}} \theta\right)}\right). \\ $$