Even more sequences

Problem:


Solution:

The easiest way is to do a plot and see



Now it is obvious it is a straight line


The equation can be found by just any method, say, by two point form

$ \frac{y - 3}{x - 2} = \frac{7 - 3}{3 - 2} $
That gives $ y = 4x - 5 $,

Therefore the answer is $ A_n = 4n - 5 $