Difficulty: Easy
Correct Answer: 64
Explanation:
Introduction / Context:This series is built from a simple formula pattern. Spotting a single wrong value requires recognizing that each term follows the same rule relating its position to a basic function.
Given Data / Assumptions:
Concept / Approach:Test the hypothesis a(n) = n^2 + 1, a very common construct in such sequences, where n starts at 1.
Step-by-Step Solution:
n = 1: 1^2 + 1 = 2 ✔n = 2: 2^2 + 1 = 5 ✔n = 3: 3^2 + 1 = 10 ✔n = 4: 4^2 + 1 = 17 ✔n = 5: 5^2 + 1 = 26 ✔n = 6: 6^2 + 1 = 37 ✔n = 7: 7^2 + 1 = 50 ✔n = 8: 8^2 + 1 = 65, not 64 ✖Verification / Alternative check:Replacing the final 64 with 65 gives a perfect match for a(n) = n^2 + 1 across all positions. No other term breaks the pattern.
Why Other Options Are Wrong:
Common Pitfalls:Assuming a difference-based rule and missing the simpler square-plus-one formula; ignoring that only the last item fails the test.
Final Answer:64
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