The screenshot from Excel is kind of irrelevant, because that doesn’t connect to Glide.
If you can show what your GoogleSheet looks like, it would be easier to provide some guidance/assistance.

I’d have to dig into it further to see what the excel equivalent is with the formulas, but I think you might be able to use something like INDIRECT or ROW to dynamically build a cell reference from another cell or from the row number. Also thinking you could maybe do something where you multiply a row number by 6 or add 6 for example to let the drag down auto increment properly…But as I look at your screenshot, I’m not sure how a drag down formula would work because you would have multiple years that you are trying to sum in the same column. Where is that summarized total supposed to be stored? Do you have the same number of equipment manufactures, or can that number change?

Unless I’m misunderstanding, I don’t think you want a formula to drag down. Instead you might want a formula in a single cell that adds up the totals for every nth row. Something like this: