How do you repeat a value x times then move on to the next cell below for the same?

Hi everyone, just joined. So, I have a question regarding duplicating a cell on another sheet x times, then moving to the next row in the column, repeating that one the same number of times, etc. I have this, which works for the first cell if I have a formula in A1 referencing the other sheet:

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Dim X As Long, LastRow As Long

LastRow = Range("A" & Rows.Count).End(xlUp).Offset(1, 0).Row
Application.ScreenUpdating = False
X = Range("C1").Value

If X = "" Or X = 0 Then Exit Sub

Range("A2:A" & LastRow).ClearContents
Range("A1").Select
Selection.AutoFill Destination:=Range("A1:A" & X), Type:=xlFillDefault
Range("A1").Select
Range("C1").Value = ""
End Sub

Any help would be great. I have 250ish unique cells in the same column that I need repeated 49 times all in the same column on another sheet. Thanks!