#include <bits/stdc++.h>

using namespace std;

#define ll long long

void solve(){
    int n;
    cin >> n;

    vector<int> a(n);
    map<int,vector<int>> mp;
    for (int i = 0;i < n;i++){
        cin >> a[i];
        mp[i - a[i]].push_back(a[i]);
    }
    ll ans = 0;
    for (auto [_,b] : mp){
        sort(b.begin(),b.end(),greater<>());
        for (int i = 0;i < b.size();i++){
            if (b[i] >= 0 && i + 1 < b.size() && b[i + 1] >= 0){
                ans += b[i] + b[i + 1];
                i++;
            }else if (b[i] >= 0 && i + 1 < b.size() && b.back() + b[i] > 0){
                ans += b[i] + b.back();
                i++;
            }else break;
        }
    }
    cout << ans << "\n";
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int t;
    cin >> t;

    while (t--){
        solve();
    }

    return 0;
}