To put you on the wrong track, there are often a few exceptions in a test series. We've worked out some common exceptions so you can spot them more easily when you come across them. If you memorize these patterns and a number of variations on these patterns, you can recognize them relatively easily.
The most well known one is the fibonacci sequence:
The 3rd number is the 1st plus the 2nd number. The 4th number is the 2nd plus the 3rd number etc. The answer is 34.
Or the variant where the three previous numbers are added:
The answer is 37.
We will work out the 3 most common exceptions and you can do 3 practice exercises yourself to see if you can recognize the patterns.