Pearson's Formula Error

Sorry to post another question so soon but I'm working on a research paper and my professor is slow to respond while you guys are light speed.

Ok so here's an example of my data that I'm working with:
1 3
1 4
1 3

When I go to do Pearson's forumal on that set I get the #DIV/0! error. I've learned that I'm getting that error because the denominator is the same, all 1s. What I'm confused about then is how do I see if there's a correlation between the two variables using pearson's formula.

If I can't use Pearson's formula than I'm wondering what else would work.