import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
        int a = Integer.parseInt(bf.readLine());
        String[] s = bf.readLine().split(" ");
        int[] k=new int[1000001];
        for(int i=0; i<a; i++){
            int x=Integer.parseInt(s[i]);
            k[x]++;
        }
        long p=0;
        for(int i=1; i<=1000000; i++){
            for(int j=i; 2L*i*j+1<=1000000; j++){
                p+=k[i*j]&k[2*i*j+1];
            }
        }
        System.out.println(p);
    }
}