Answer
A good strategy to discover a pattern would be to organize data in a tabular form, which will work as an "input - output" machine. It will take a value as an input, process it and give a value as an output. The process column of the table would help to understand the relationship between the input and output.
Work Step by Step
A strategy would be to look at each number to see if there is a common difference or factor between each of the numbers. That is to say if n (any number) were to have the common difference or common factor, then it would fall into that pattern.
