Sub Singleton1()
Dim deb, t, dico, x, q&
deb = Timer
t = Range(Cells(3, 1), Cells(Rows.Count, 1).End(xlUp))
Set dico = CreateObject("scripting.dictionary")
For Each x In t: dico(x) = dico(x) + 1: Next
For Each x In dico
If dico(x) = 1 Then q = q + 1 Else dico.Remove x
Next x
If q > 0 Then
ReDim r(1 To q, 1 To 1): q = 0
For Each x In dico
If dico(x) = 1 Then q = q + 1: r(q, 1) = x
Next x
End If
MsgBox Format(Timer - deb, "0.00\ sec.")
End Sub