
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
Let $S_{n}$ be the sum of the first $n$ terms of the sequence ${a_{n}}$. If $S_{n}=3^{n}-1$, then the sum of the squares of the first $n$ terms, $a_{1}^{2}+a_{2}^{2}+a_{3}^{2}+...+a_{n}^{2}$, equals \_\_\_\_\_\_.

Present the answer in LaTex format: \boxed{Your answer}
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