How to plot a complex table relation on excel?

How can I generate a table as displayed in the image attached using Microsoft excel. The x and y axis in yellow are simply perfect squares while The table content is composed of axis sums. I caot generalize a cell formula to correctly sum the y and x axis for any cell.

The problem a am facing is this.Lets say I want to compute the value of cell B3, I can manually enter into the cell: =(B1+A3). However i caot duplicate this formula onto other cells to give the desired outcome.

I need a generalized formula for any cell. I am thinking along the lines: =(letterofgivencell 1 + numberofgivencell [A].

I need the table to investigate pattes in pythagorean triples and the automation would be helpful.

attached image