Let \( a_{1}, a_{2}, \ldots, a_{n} \) be in A.P. If \( a_{5} = 2a_{7} \) and \( a_{11} = 18 \), then \( 12\!\left(\dfrac{1}{\sqrt{a_{10}}+\sqrt{a_{11}}} + \dfrac{1}{\sqrt{a_{11}}+\sqrt{a_{12}}} + \ldots + \dfrac{1}{\sqrt{a_{17}}+\sqrt{a_{18}}}\right) \) is equal to _____.
