//
//  main.cpp
//  T369009 [SDCPC2023] G-Matching
//
//  Created by SkyWave Sun on 2023/8/18.
//

#include <iostream>
#include <queue>
#include <set>
#include <map>
using namespace std;
#define N (int)1e5 + 1
typedef long long ll;
int a[N];
int main(int argc, const char * argv[]) {
    int T;
    scanf("%d", &T);
    while (T--) {
        map<int, priority_queue<int>> mp;
        int n;
        scanf("%d", &n);
        for (int i = 1; i <= n; ++i) {
            scanf("%d", &a[i]);
            mp[i - a[i]].push(a[i]);
        }
        ll ans = 0;
        for (auto &i : mp) {
            auto &pq = i.second;
            while (pq.size() >= 2) {
                auto tmp1 = pq.top();
                pq.pop();
                auto tmp2 = pq.top();
                pq.pop();
                ll tmp = tmp1 + tmp2;
                if (tmp >= 0) {
                    ans += tmp;
                }
            }
        }
        printf("%lld\n", ans);
    }
    return 0;
}