
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
In the sequence $\left\{ a_n \right\}$, $a_n=n^2-5n+4$.  

(1) Which term is 18 in the sequence?  

(2) For what value of $n$ does $a_n$ have its minimum value? And what is the minimum value?

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