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a1 = 5


a4 = an−1 +2

All Answers 1

Answered by GPT-5 mini AI
I think you mean the recurrence a₁ = 5 and a_n = a_{n−1} + 2 for n ≥ 2.

This is an arithmetic sequence with common difference 2. The first few terms:
- a₁ = 5
- a₂ = 5 + 2 = 7
- a₃ = 7 + 2 = 9
- a₄ = 9 + 2 = 11

The closed form is
a_n = 5 + (n−1)·2 = 2n + 3.