Найти сумму первых n членов заданной последовательности

function factorial(n: integer): real;
begin
if n > 1
then factorial := n * factorial(n-1)
else factorial:= 1;
end;
 
procedure TForm1.Button1Click(Sender: TObject);
var
k,n:Integer;
s:real;
begin
s := 0;
n := StrToInt(Edit1.Text);
for k := 0 to n do s := s + 1/factorial(2*k);
Label1.Caption := FloatToStr(s);
end;

function factorial(n: integer): extended;
begin
if n > 1
then factorial := n * factorial(n-1)
else factorial:= 1;
end;
 
procedure TForm1.Button1Click(Sender: TObject);
var
k,n:Integer;
s:extended;
begin
s := 0;
n := StrToInt(Edit1.Text);
for k := 0 to n do s := s + 1/factorial(2*k);
Label1.Caption := FloatToStr(s);
end;

else factorial:= 1;

function fuct(n:integer):Extended;
var i:integer;
  tmp:extended;
begin
  tmp:=1;
  if n>1 then
    begin
      for i:=1 to n do
        tmp:=tmp*i;
      fuct:=tmp
    end
  else
    fuct:=1;
end;
 
procedure TForm1.btn1Click(Sender: TObject);
var
  k,n:integer;
  s:real;
begin
  n:=10;
  s:=0;
  for k:=0 to n do s:=s+1/(fuct(k*2));
  showmessage(Floattostrf(s,ffFixed,2,3));
end;