Sub SupprimeLignesPaires()
Dim t#, P As Range
t = Timer
Application.ScreenUpdating = False
Set P = ActiveSheet.UsedRange
P.Columns(1).Insert xlToRight 'colonne auxiliaire
P(1, 0) = 1: P(2, 0) = "a" 'un nombre, un texte
P(1, 0).Resize(2).AutoFill P(1, 0).Resize(P.Rows.Count), xlFillValues
With P(1, 0).Resize(P.Rows.Count, P.Columns.Count + 1)
.Sort P(1, 0), xlAscending 'le tri met les "a" en bas
.Columns(1).SpecialCells(xlCellTypeConstants, 2).EntireRow.Delete
.Columns(1).Delete xlToLeft 'supprime la colonne auxiliaire
End With
MsgBox "Durée " & Format(Timer - t, "0.00 \s")
End Sub