Linear Regression (Caclulus/Statistics)

Here's my situation - I have a table, where x is always incremented by 1: 1, 2, 3, 4, etc... and then the y is a mystery - but I know it's consistent. I need to find the equation for the line that is created. I know that all the data points are EXACTLY on the line. I was told that Linear (or Least Squares) regression is a good solution, but so far, I've only found a method for determining how good the line of best fit is once you've found it. My line of best fit would be exact (in other words, r=1), and I need to know how to FIND THE LINE, not test it. Anyone have any ideas? I was told about an equation involving a whole lot x and ys squared with epsilons all over the place. Ring a bell?