
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
If $n\in N^*$, let the ordinate of the point where the tangent line of the curve $y=x^n(1-x)$ at $x=2$ intersects the $y$-axis be $a_n$. Then the sum of the first $n$ terms of the sequence $\{\frac{a_n}{n+1}\}$ is _______.

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