Sorry, can't open your file...

What about this? As I understand that's mainly what you are looking for (taking into account I don't know what are you trying to calculate from this 2 inputs).
Sub test()
Offset = 2
Set ws = ThisWorkbook.Worksheets(1)
For n = 1 To 40
    For p = 1 To 100
        ws.Cells((n - 1) * 100 + p - 1 + Offset, 2).Value = n
        ws.Cells((n - 1) * 100 + p - 1 + Offset, 3).Value = p
        ws.Cells((n - 1) * 100 + p - 1 + Offset, 4).Formula = "=RC[-1]*RC[-2]"
    Next p
Next n
End Sub