arrays - Excel macro code for every 2nd row to increase by 1

Question

I have a list of numbers (over 100 rows). I want every 2nd number in each group of 3's row to increase by 1 from its previous row.

Think in groups of 3. The first value is given. The 2nd value is 1 higher than the first, and the 3rd value can be anything. This pattern continues for the next 3. For example, if Row 1 = 1, Row 2 = 2 (because increase 1 from previous row). Row 3 = any #. Row 4 = 5, Row 5 = 6 (because increase 1 from previous row). Row 6 = any number. Row 7 = 7, Row 8 = 8 (because 1 from orevious), Row 9 = any.

I can't figure out how to loop through this. THis is what I tried.

Sub DoSomething
  For ColNum = 4 To 500 Step 2
    Range(Cells(3, ColNum), Cells(1159, ColNum)).FormulaR1C1 = "='H2'+1"
  Next ColNum
End Sub 

Answer 1

If I understand your question correctly, you may want somthing like:

Sub test()

For i = 3 To 1159 Step 3

     Cells(i + 1, 1).FormulaR1C1 = "=R[-1]C+1"

Next i

End Sub

Starting in Row 3, up to row 1159, in sets of 3, grab the next cell and enter a formula that increases the value of the cell in the row above by 1.

Here are screenshots to illustrate the code. Left is before, right is after. Column B has =Formulatext(A3) copied down.

Thinking in groups of three, every second cell in each group of three is treated to the formula.