Macro modification required (very small)

Dear all,
How to add same formula in different sheet ? below macro is running fine for the sheet "i6" very well.
but now i want to add more sheet like (i7,i8,i9,i10,i11,i12,i13,i14,i15) so that when ever i run macro
each & every sheet having same formula at a time. here one things i can create sheet wise macro
but it makes the the overall macro bigger & also size is factor. i need your assistance...

Sub EnterFormula()
With Sheets("i6")  ' here i want to add more sheet like (i7,i8,i9,i10,i11,i12,i13,i14,i15)
.Range("AB6").Formula = "=IF(COUNT(BD6:BL6)=0,"""",SUM(BD6:BL6)/9)"  ' in every sheet need to put same formula 
End With
End Sub