#include <iostream>
using namespace std;
using ll = long long;

int main(void){
    ios::sync_with_stdio(0); cin.tie(0);
    int a[1'000'005]{0};
    int n; cin >> n;
    for (int i = 0; i < n; i++){
        int v; cin >> v;
        a[v] = 1;
    }
    int ans = 0;
    for (int i = 1; i <= 1'000'000; i++){
        if (a[i] == 0 || (i%2 == 0 && i % 4 > 0))
            continue;
        int j = i;
        for (int d = 2 - j%2; d*d < j; d+=2){
            if (j % d)
                continue;
            int d2 = j / d;
            ans += a[(d2-d)/2];
        }
    }
    cout << ans << "\n";
}