Identify the number that does NOT belong to the following series.

7 15 32 67 136 281 ​​

Information Given:
Series: 7, 15, 32, 67, 136, 281

Logic: Multiply by 2 and add consecutive natural numbers.

Explanation:
7 × 2 + 1 = 15
15 × 2 + 2 = 32
32 × 2 + 3 = 67
67 × 2 + 4 = 138 (not 136) ✘
Correct term should be 138

Then,
138 × 2 + 5 = 281 ✔

Thus, 136 is incorrect.

Short Trick:
Check pattern: ×2 + 1, +2, +3, +4…

Final Answer:
136

Final Correct Option:
(C)