
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
Given that the sequence {a<sub>n</sub>} is an arithmetic sequence with a non-zero common difference, a<sub>1</sub> = 1, and there exists a real number λ such that 2a<sub>n+1</sub> = λa<sub>n</sub> + 4, n ∈ N<sub>+</sub>.
(1) Find the value of λ and the general term a<sub>n</sub>;
(2) Find the sum S<sub>n</sub> of the first n terms of the sequence {a<sub>2^n - n</sub>}.

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