Formule excel

Option Explicit
'-----------------------------------
Sub numéros_manquants()
Dim Derlig As Long, T_colA, T_colB, Cpta As Long, Cptb As Integer, Diff As Integer, Inc As Integer

    Application.ScreenUpdating = False
    Derlig = Columns("A").Find(what:="*", searchdirection:=xlPrevious).Row
    T_colA = Application.Transpose(Range("A2:A" & Derlig))
    Range("B2:B1000000").Clear
    ReDim T_colB(1 To UBound(T_colA))
   
    For Cpta = 2 To UBound(T_colA)
        If T_colA(Cpta) - T_colA(Cpta - 1) > 1 Then
                Diff = T_colA(Cpta) - T_colA(Cpta - 1)
                For Inc = 1 To Diff - 1
                    Cptb = Cptb + 1
                    T_colB(Cptb) = T_colA(Cpta - 1) + Inc
                Next
        End If
    Next
    Range("B2").Resize(UBound(T_colB), 1) = Application.Transpose(T_colB)
End Sub