Combinaison de deux lettres ou numeros...

Sub test()

Dim Arr(), Elt As Variant, T()
Dim C As Long, A As Long, B As Long

Arr = Array("A", "B", "C", "D")

For Each Elt In Arr
    For C = 0 To UBound(Arr)
        A = A + 1
        ReDim T(1 To A)
        B = B + 1
        T(A) = Elt & Application.Index(Arr, B)
    Next
    B = 0
Next

With Worksheets("Feuil1")
    .Range("A1").Resize(A) = Application.Transpose(T)
End With

End Sub

Sub test()

Dim Arr(), Elt As Variant, T()
Dim C As Long, A As Long, B As Long

 Arr = Array("A", "B", "C", "D")

For Each Elt In Arr
     For C = 0 To UBound(Arr)
        If Arr(C) <> Elt Then
            A = A + 1
            ReDim T(1 To A)
            B = B + 1
            T(A) = Elt & Application.Index(Arr, B)
        Else
            B = B + 1
        End If
     Next
     B = 0
Next

With Worksheets("Feuil1")
     .Range("A1").Resize(A) = Application.Transpose(T)
End With
End Sub