depends on where the sequence of numbers has come from. If it is from a build up of say poctorial patterns, like many GCSE maths coursworks do, then create the next few terms to investigate the differences between them and the differences of the differences etc. From there you can work out the type of power sequence you are dealing with.
Common first difference of "a" then Linear sequence of the form an where "n" is the position
Common 2nd difference of "a" then a quadratic sequence of (a/2)n^2
Common 3rd difference the cubic of form (a/6)n^3
etc
If the sequence is given as a set of numbers and you have found no common difference at the first few levels, 1st, 2nd 3rd etc, you can use a general formulae eg given 5 terms the sequnce could at most be n^4
Let the 5 terms by Z, Y, X, W, and V
then use an^4+bn^3+Cn^2+dn+e=... Z when n=1, Y when n=2 X when n=3 etc. 5 independent equations 5 unknowns so solvable.