
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 finite sequence $a_1, a_2, a_3, \ldots, a_n$ (where $n$ is a positive integer) that satisfies the conditions $a_1 = a_n$, $a_2 = a_n-1$, $\ldots$, $a_n = a_1$, i.e., $a_k = a_{n-k+1}$ (for $k=1, 2, \ldots, n$), we call it a "symmetric sequence". Let $\{b_n\}$ be a symmetric sequence with 7 terms, where $b_1, b_2, b_3, b_4$ form an arithmetic sequence, and $b_1 = 2$, $b_2 + b_4 = 16$. List the terms of $\{b_n\}$ in order.

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