
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, satisfying $$\overrightarrow {OA} = a_{3} \overrightarrow {AB} + a_{2016} \overrightarrow {AC}$$, where A, B, C are on the same line, and O is a point outside line AB. Denote the sum of the first n terms of the sequence $\{a_n\}$ as $S_n$, then calculate the value of $S_{2018}$.

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