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

void solve() {
	int n;
	cin >> n;
	vector<array<int, 2>> a(n + 1);

	for (int i = 1; i <= n; i++) {
		int x;
		cin >> x;
		a[i] = {i - x, x};
	}

	sort(a.begin() + 1, a.end());

	int ans = 0;
	for (int i = 1; i <= n; i++) {
		int j = i;
		while (j + 1 <= n && a[j + 1][0] == a[i][0]) {
			j++;
		}
		int k = i + ((j - i + 1) % 2);
		for (; k <= j; k += 2) {
			ans += max(0LL, a[k][1] + a[k + 1][1]);
		}
		i = j;
	}

	cout << ans << "\n";
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    
    int T;
    cin >> T;
    while (T--) solve();

    return 0;
}