#include <bits/stdc++.h>
#define int long long
using namespace std;
int32_t main()
{
    cin.tie(nullptr)->sync_with_stdio(false);
    int n;
    cin >> n;
    vector<int> a(n + 1);
    for (int i = 1; i <= n; ++i)
    {
        cin >> a[i];
    }
    set<pair<int, int>> ans;
    for (int i = 1; i <= n; ++i)
    {
        for (int k = 2; k * i <= a[i]; ++k)
        {
            int left = a[i] - k * i;
            if (left % (k - 1) == 0)
            {
                int j = left / (k - 1);
                if (j >= 1 && j <= n && i != j)
                {
                    if (__gcd(a[i] + j, a[j] + i) == i + j)
                    {
                        ans.insert({min(i, j), max(i, j)});
                    }
                }
            }
        }
    }
    int fixedpoints = 0;
    for (int i = 1; i <= n; ++i)
    {
        if (a[i] == i)
        {
            fixedpoints++;
        }
    }

    cout << (int)ans.size() + fixedpoints * (fixedpoints - 1) / 2;
}