
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 the sequence \(\left(a_{n}\right)_{n=1}^{\infty}\) with \(a_{1}=a_{2}=2\), and the recurrence relation
\[ \frac{2 a_{n-1} a_{n}}{a_{n-1} a_{n+1}-a_{n}^{2}}=n^{3}-n \]
for all \(n=2,3,4, \ldots\), find the integer that is closest to the value of \(\sum_{k=2}^{2011} \frac{a_{k+1}}{a_{k}}\).

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