Jason Hancock wrote:

Well, I've tried several different things, but have not been successful.
I'm trying to sum every third row of a particular column (i.e.
A2+A5+...)

Without using VBA you can insert the following in the first cell of an
empty column (say, Column N)

=INDIRECT("A"&3*ROW()-1)

Then in the first cell of the next column (say, Column O)

=SUM(N:N)

The desired result will be in Cell O1

Alan Beban