#include <bits/stdc++.h>
using namespace std;
#define repl(i, l, r) for (ll i = (l); i < (r); i++)
#define rep(i, n) repl(i, 0, n)
#define CST(x) cout << fixed << setprecision(x)
using ll = long long;
constexpr ll MOD = 1000000007;
constexpr int inf = 1e9 + 10;
constexpr ll INF = (ll)4e18 + 10;
constexpr int dx[9] = {1, 0, -1, 0, 1, -1, -1, 1, 0};
constexpr int dy[9] = {0, 1, 0, -1, 1, 1, -1, -1, 0};
template <class T>
inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b;
        return true;
    }
    return false;
}
template <class T>
inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
int main() {
    cin.tie(0);
    cout.tie(0);
    ios::sync_with_stdio(false);

    int n;
    cin >> n;
    int a[n];
    rep(i, n) cin >> a[i];
    vector<ll> dp(n);
    dp[0] = 1;
    rep(i, n - 1) {
        if (dp[i] == 0) continue;
        for (int j = i + a[i]; j <= n; j += a[i]) {
            dp[j] += dp[i];
            dp[j] %= MOD;
        }
        if (a[i] > 1) dp[i + 1] = (dp[i + 1] + dp[i]) % MOD;
    }
    cout << dp[n - 1] << endl;
    return 0;
}