#include<bits/stdc++.h>

using namespace std;
#define endl '\n'
// #define int long long

long long M = 998244353;
typedef long long LL;
typedef pair<int, int> PII;

int n;
void solve() {
	cin >> n;
	vector<int> a(n + 1);
	for(int i = 1; i <= n; i++) cin >> a[i];
	// vector<int>
	LL ans = 0;
	
	map<int, int> mp;
	vector<LL> b[n + 1];

	int idx = 0;
	for(int i = 1; i <= n; i++) {
		int d = a[i] - i;
		if(!mp.count(d)) {
			mp[d] = ++idx;
			b[idx].push_back(0);
		}
		b[mp[d]].push_back(a[i]);
	}
	// for(int i = 1; i <= idx; i++) {
	// 	for(auto c: b[i]) cout << c << ' ';
	// 		cout << endl;

	// }

	for(int i = 1; i <= idx; i++) {
		sort(b[i].begin() + 1, b[i].end());
		
		int  r = b[i].size() - 1;
		while(r > 1) {
			LL rr = b[i][r], ll = b[i][r - 1];
			if(ll + rr >= 0)  ans += ll + rr;

			r -= 2;
		}


	}



	cout << ans << endl;



}

int main() {
	int t;
	cin >> t;
	while(t--) solve();



}