
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 with a common difference of $0$, and ${a_{1}}=1$, ${a_{1} }$, ${a_{3} }$, ${a_{6} }$ form a geometric sequence, find the sum of the first $n$ terms, $S_n$, of the sequence $\{{a_{n} }\}$.

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