Procedure TForm1.Button1Click(Sender: TObject);
var
  i, k: integer;
  s: string;
begin
  k := 0;
  i := 1;
  while k 8 do
  begin
    if (i mod 7 = 0) then
    begin
      s := s + IntToStr(i) + #13;
      Inc(k);
    end;
    Inc(i);
  end;
  ShowMessage(s);
end;