Option Explicit
Sub Recap()
Dim X As Integer
Range("C2:F500").ClearContents
Application.ScreenUpdating = 0
For X = 2 To Sheets.Count
With Sheets("Sommaire")
.Range("C" & X).Value = Sheets(X).Name
.Range("D" & X).Formula = "=IF(RC3="""","""",COUNTA(INDIRECT(""'""&RC3&""'!C:C""))-1)"
.Range("E" & X).Formula = "=IF(RC3="""","""",COUNTA(INDIRECT(""'""&RC3&""'!AI:AI""))-1)"
.Range("F" & X).Formula = "=IF(RC3="""","""",RC[-2]-RC[-1])"
End With
Next X
End Sub