Let $\displaystyle x_n$ be the sequence with $\displaystyle x_1=2$ and $\displaystyle x_n=\sqrt{5(x_{n-1})+6}$ for every integer $\displaystyle n\geq 2$. How can this be written in summation notation?

$\displaystyle x_1=2$

$\displaystyle x_2=\sqrt{16}=4$

$\displaystyle x_3=\sqrt{26}$

$\displaystyle x_4=\sqrt{5\big(\sqrt{26}\big)+6}$

$\displaystyle x_5=\sqrt{5\bigg(\sqrt{5\big(\sqrt{26}\big)+6}\big g)+6}$

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