Private Sub Worksheet_Change(ByVal Target As Range)
'il faut titre en A1
If Intersect(Target, [A:A]) Is Nothing Then Exit Sub
Dim t1, t2, i As Long, mem As Boolean
t1 = Range("A1", Cells(Rows.Count, 1).End(xlUp))
t2 = t1
On Error Resume Next 'si le tableau n'a qu'un élément
For i = 2 To UBound(t1)
If t1(i, 1) <> t1(i - 1, 1) Then mem = Not mem
t2(i, 1) = mem
Next
ThisWorkbook.Names.Add "Test", t2 'nom défini sur matrice
End Sub