Code to create numbers in sequence

Also mine corrected:

Sub test()
Dim i As Long, j As Long, k As Long, current As Long, cell As Range, prefix As String
Application.ScreenUpdating = False
For k = Cells(Rows.Count, "A").End(xlUp).Row To 1 Step -1
  Set cell = Cells(k, 1)
  current = Val(IIf(InStr(cell, "-"), Right(cell, Len(cell) - InStrRev(cell, "-")), cell))
  prefix = Replace(cell, current, "")
  j = Val(cell.Offset(0, 1))
  If j > 0 Then
    cell.Offset(1, 0).Resize(j, 1).EntireRow.Insert
    For i = 1 To j
      current = current + 1
      Cells(k + j, 1) = IIf(Len(prefix), prefix & current, current)
    Next i
  End If
Next k
End Sub

Slower one, but could be (who knows ) a bit easier to understand