Private Sub Worksheet_Change(ByVal Target As Range)
With Target
If Not Intersect([AA2:AA500], .Cells) Is Nothing Then
With [Sheet2!B3:B79]
.Formula = "=IF(C3="""","""",3^COUNT(MATCH(C3,AA$2:AA$500,)))"
.Value = .Value
End With
[Sheet2!D1] = Now
End If
End With
End Sub