#include <bits/stdc++.h>
using namespace std;

using i64 = long long;

int __OneWan_2024 = [](){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	return 0;
}();

void solve() {
    map<int, vector<int>> mp;
    int n;
    cin >> n;
    for (int i = 1 ; i <= n ; i++) {
        int x;
        cin >> x;
        mp[i - x].push_back(x);
    }
    i64 ans = 0;
    for (auto &[_, vec] : mp) {
        sort(rbegin(vec), rend(vec));
        // for (auto &x : vec) {
        //     cout << x << " ";
        // }
        // cout << "\n";
        for (int i = 0 ; i + 1 < (int) vec.size() ; i += 2) {
            if (vec[i] + vec[i + 1] > 0) {
                ans += vec[i] + vec[i + 1];
            }
        }
    }
    cout << ans << "\n";
}

int main() {
    int T;
    cin >> T;
    while (T--) {
        solve();
    }
	return 0;
}