var fi,fo:text;
    n,x,nr_div:longint;
    ct:byte;
    rez:int64;
    i,j:longint;
    nr:array[1..1000001]of byte;
    m:array[1..1000001]of longint;
procedure prim(nr:longint);
var i:longint;
begin
  i:=2; nr_div:=0; ct:=1;
  while i<=trunc(sqrt(nr)) do
    begin
      if nr mod i=0 then 
        begin
         if nr mod (i*i)=0 then begin ct:=2; exit; end;
         inc(nr_div); 
         nr:=nr div i; 
        end;
      inc(i);
    end;
    if nr>1 then inc(nr_div);
end;
procedure verif(i:longint);
var ok:boolean;
begin
  prim(i); 
  if ct=1 then
    if nr_div and 1 = 1 then rez:=rez + (m[i]*(m[i]-1)) shr 1
                        else rez:=rez - (m[i]*(m[i]-1)) shr 1; 
end;
begin
  assign(fi,'pairs.in'); reset(fi);
  assign(fo,'pairs.out'); rewrite(fo);
  readln(fi,n);
  max:=-maxint;
  rez:=0;
  for i:=1 to n do
    begin
      readln(fi,x);
      nr[x]:=1;
    end;
  for i:=2 to 1000000 do
    begin
      for j:=1 to 1000000 div i do
         if nr[i*j]=1 then inc(m[i]);
      if (m[i]>0) then verif(i);
    end;
  rez:=(n*(n-1) shr 1) - rez;
  writeln(fo,rez);
  close(fi);
  close(fo);
end.