
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
Let the sequence $\{a_n\}$ be defined by:
- $a_1 = 3$
- $a_{n+1} = a_n + 2n + 4$ for $n \geq 1$.

Determine $a_{50}$.
A) 2646
B) 2647
C) 2648
D) 2649

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