Looping through a number count in quotes in VBA - vba

Question

I am making a table in VBA, and as you can see in my sample table here, I have certain merges about every 2 rows of cells made dependent on various cells. However, a part of the table that can be static is column C in the dark gray. I simply want it to do a number count starting at 1 and continuing to the end of my table but skipping the red horizontal lines and leaving them blank. So, red would be 1, orange 2, yellow 3, etc. Here is the code I want to make more efficient. I could type out every number, but that just seems so inefficient.
range("C3:C8").Select
ActiveCell.FormulaR1C1 = "1"
With Selection
.MergeCells = True
.HorizontalAlignment = xlCenterAcrossSelection
.VerticalAlignment = xlBottom
End With
range("C10:C12").Select
ActiveCell.FormulaR1C1 = "2"
With Selection
.MergeCells = True
.HorizontalAlignment = xlCenterAcrossSelection
.VerticalAlignment = xlCenter
End With
range("C9:C10").Select
ActiveCell.FormulaR1C1 = "3"
With Selection
.MergeCells = True
.HorizontalAlignment = xlCenterAcrossSelection
.VerticalAlignment = xlCenter
End With

Answer 1

I would use that there is text in column D.
Sub add_counter()
'Created by Fredrik Östman www.scoc.se
counter = 1
For i = 7 To ActiveSheet.UsedRange.Rows.Count + ActiveSheet.UsedRange.Row
If Cells(i, 4) <> "" Then
Cells(i, 3) = counter
With Range(Cells(i, 3), Cells(i + 1, 3))
.MergeCells = True
.HorizontalAlignment = xlCenterAcrossSelection
.VerticalAlignment = xlBottom
End With
counter = counter + 1
End If
Next i
End Sub