Hard Number Series Aptitude Riddle

Hard Number Series Aptitude Riddle Solution - 27 June

What is the next number in the series.

15 29 56 108 208 ?

Update Your Answers at : Click Here

Solution
400

Explanation:
15
2*15-1 => 29
2*29-2 => 56
2*56-4 => 108
2*108-8 => 208
2*208-16 => 400