
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
The first term of the sequence $\{a_{n}\}$ is $a_{1}=1$. The sequence $\{b_{n}\}$ is a geometric sequence, and $b_{n}= \frac {a_{n+1}}{a_{n}}$. If $b_{10}b_{11}=2016^{\frac{1}{10}}$, then $a_{21}=$ \_\_\_\_\_\_.

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