The odd number in the series is 216.

Uncovering the Pattern

The pattern for this series is n³ + 1, where 'n' is the term's position in the sequence, starting with n=1.

Let's check each number against the rule:

• 1³ + 1 = 1 + 1 = 2 (Correct)
• 2³ + 1 = 8 + 1 = 9 (Correct)
• 3³ + 1 = 27 + 1 = 28 (Correct)
• 4³ + 1 = 64 + 1 = 65 (Correct)
• 5³ + 1 = 125 + 1 = 126 (Correct)
• 7³ + 1 = 343 + 1 = 344 (Correct)

The sixth number in the series is the one that breaks the pattern:

• The correct number should be: 6³ + 1 = 216 + 1 = 217.
• The number given in the series is 216.

Therefore, 216 is the odd number in the series.