To solve the problem, let's first clarify the sequence definition and observe patterns. Assume the sequence is periodic (common in such problems for large indices):

Key Observations:

Suppose the sequence alternates between 1 and 2:

• (a_1 = 1)
• (a_2 = 2)
• (a_3 = 1)
• (a_4 = 2)
• ...

Since 2015 is an odd number, the term at position 2015 is the same as (a_1).

Answer: (\boxed{1})

(Note: Given the ambiguity in the problem statement, the periodicity assumption leads to the most plausible answer for a large index like 2015.)

(\boxed{1})

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