Number stack formula/Macro?

In the sheet's code put

Option Explicit

Private Sub Worksheet_Change(ByVal Target As Range)
Const WkCeAd = "A1"
    If (Target.Address <> Range(WkCeAd).Address) Then Exit Sub
    Application.EnableEvents = False
    Range(WkCeAd)(2, 1).Insert Shift:=xlDown
    Range(WkCeAd)(3, 1).Copy
    Range(WkCeAd)(2, 1).PasteSpecial Paste:=xlPasteFormats
    Range(WkCeAd)(2, 1) = Range(WkCeAd)
    Range(WkCeAd) = ""
    Application.EnableEvents = True
End Sub