Thats for questions 3 - 8 that you didn't answer. I'm not quite sure how to answer the last two though.
Well I think it can help even better because since you already solved and proved your work you know what to do for your answer.
I think
Answer:
i think it's the third one
Step-by-step explanation:
an = a1 + 4×[2^(n -1) - 1]
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