
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 that the sequence $\{a_n\}$ is an arithmetic sequence, and it satisfies $\overrightarrow{OA} = a_3\overrightarrow{OB} + a_{2015}\overrightarrow{OC}$, where points $A$, $B$, $C$ are on a straight line, and point $O$ is a point outside the line $AB$. Let the sum of the first $n$ terms of the sequence $\{a_n\}$ be $S_n$, then calculate the value of $S_{2017}$.

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