var n,i,m:longint;
    a,v:array[-1..250] of longint;

procedure combinari(c:longint);
var i:longint;
begin
  if c>3 then begin
 // for i:=1 to 3 do write(a[v[i]]); writeln;
    if (a[v[1]]+a[v[2]]>=a[v[3]])
      and (a[v[2]]+a[v[3]]>=a[v[1]])
      and (a[v[1]]+a[v[3]]>=a[v[2]]) then
        inc(m);
    end
  else begin
    for i:=v[c-1]+1 to n-3+c do begin
      v[c]:=i;
      combinari(c+1);
    end;
  end;
end;

begin
  assign(input,'nrtri.in');
  assign(output,'nrtri.out');
  reset(input);
  rewrite(output);

  read(n);
  for i:=1 to n do
    read(a[i]);
  m:=0;
  combinari(1);
  write(m);
end.