
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 a geometric sequence $\{a_n\}$ with a common ratio $q=2$, and $a_2$, $a_3+1$, $a_4$ form an arithmetic sequence.  
(1) Find $a_1$ and $a_n$;  
(2) Let $b_n=a_n+n$, calculate the sum of the first 5 terms of the sequence $\{b_n\}$, $S_5$.

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