Macro to Fill with Formula, but Hide Formula to User

So you want the code to put the formula in then replace it with values?

With Range("F2", Range("E" & Rows.Count).End(xlUp).Offset(, 1))
    .Formula = "=IF(E2=""BLANK"",E2,LOOKUP(E1,{0,6,10,15},{""<6"",""6-10"",""10-15"","">15""})&"" Days"")"
    .Value = .Value
End With