The wrong number of the sequence 4 , 9 , 19 , 39 , 79 ,

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The wrong number of the sequence 4 , 9 , 19 , 39 , 79 , 169 , 319 is

1. 169
2. 79
3. 39
4. 9

Correct Option: A

The pattern of the sequence is :
4 × 2 + 1 = 9
9 × 2 + 1 = 19
19 × 2 + 1 = 39
39 × 2 + 1 = 79
79 × 2 + 1 = 159 ≠ 169
Since , 169 is wrong number. So , correct number is 159 .