Set r = ActiveSheet.UsedRange
j = r.Rows.Count + r.Row
Set rdel = Cells(j, "A")
k = 0
For i = 1 To j - 1
k = k + 1
If k = 4 Then
k = 1
End If
If k = 3 Then
Else
Set rdel = Union(rdel, Cells(i, "A"))
End If
Next
rdel.EntireRow.Delete
Using the recorder to automate what you do manually is a very good start.
The recorder is not good for teaching about loops or conditional statements.
It goes not help to learn about ranges either.