
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
After the first "H expansion", the sequence becomes 1, 3, 2; after the second "H expansion", it becomes 1, 4, 3, 5, 2. Find the number of items in the sequence after the 10th "H expansion".

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