Your series is: 2,7,5,9,9,1,14,13,---,--- Pl check - is the 6th term 1 or 11? I think there could be a typo and it is actually 11. If so, the series is 2,7,5,9,9,11,14,13,...,... and it can be solved. Solution: Look at alternate terms - they form 2 separate series. Series 1: 2,5,9,14... where the difference between successive terms keeps increasing by 1. 2 + 3 = 5 5 + 4 = 9 9 + 5 = 14 So the next term in this series is 14 + 6 = 20 Series 2: And the other series is 7,9,13,... which is a simple arithmetic progression with difference as 2. So the next term in this series is 13 + 2 = 15. So the next two terms are 20 and 15. Hope this helps. :)