观察下列等式:
\(\left( \left. \sin \dfrac{π}{3} \right. \right)^{-2} +\left( \left. \sin \dfrac{2π}{3} \right. \right)^{-2} = \dfrac{4}{3}×1×2\);
\(\left( \left. \sin \dfrac{π}{5} \right. \right)^{-2} +\left( \left. \sin \dfrac{2π}{5} \right. \right)^{-2} +\left( \left. \sin \dfrac{3π}{5} \right. \right)^{-2} +\left( \left. \sin \dfrac{4π}{5} \right. \right)^{-2} = \dfrac{4}{3}×2×3\);
\(\left( \left. \sin \dfrac{π}{7} \right. \right)^{-2} +\left( \left. \sin \dfrac{2π}{7} \right. \right)^{-2} +\left( \left. \sin \dfrac{3π}{7} \right. \right)^{-2} +…+\left( \left. \sin \dfrac{6π}{7} \right. \right)^{-2} = \dfrac{4}{3}×3×4\);
\(\left( \left. \sin \dfrac{π}{9} \right. \right)^{-2} +\left( \left. \sin \dfrac{2π}{9} \right. \right)^{-2} +\left( \left. \sin \dfrac{3π}{9} \right. \right)^{-2} +…+\left( \left. \sin \dfrac{8π}{9} \right. \right)^{-2} = \dfrac{4}{3}×4×5\);
\(……\)
照此规律,
\(\left( \left. \sin \dfrac{π}{2n+1} \right. \right)^{-2} +\left( \left. \sin \dfrac{2π}{2n+1} \right. \right)^{-2} +\left( \left. \sin \dfrac{3π}{2n+1} \right. \right)^{-2} +…+\left( \left. \sin \dfrac{2nπ}{2n+1} \right. \right)^{-2} =\)__________.