
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
Given an arithmetic sequence $\{a\_n\}$, let $S\_n$ denote the sum of its first $n$ terms. If $\overrightarrow{OB} = a\_4\overrightarrow{OA} + a\_{2013}\overrightarrow{OC}$ and points $A$, $B$, and $C$ are collinear ($O$ being a point outside this line), find $S\_{2016}=\_\_\_\_\_\_.$

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