#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int t;
    cin >> t;
    while(t--){
        int n;
        cin >> n;
        vector<long> a(n);
        for (int i = 0; i < n; ++i){
            cin >> a[i];
        }
        long maxval = 0;
        for (int i = n-1; i >=0; --i){
            if (a[i] + i < n){
                a[i] = a[i] + a[i + a[i]];
            }
            if (a[i] > maxval){
                maxval = a[i];
            }
        }
        cout << maxval << endl;
    }
}