
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
Find the sum of the following \( n^2 \) numbers:
$$
\begin{array}{l}
1, 2, 3, \cdots, n \\
2, 3, 4, \cdots, n+1 \\
3, 4, 5, \cdots, n+2 \\
\cdots \cdots \\
n, n+1, n+2, \cdots, 2n-1
\end{array}
$$

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