#pragma GCC optimize(2)
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define PII pair<int, int>
struct node
{
	int num;
	int minu;
} N[100005];
bool cmp(node a, node b)
{
	return a.minu < b.minu;
}
void solve()
{
	int n;
	cin >> n;
	for (int i = 1; i <= n; i++)
	{
		cin >> N[i].num;
		N[i].minu = N[i].num - i;
	}
	sort(N + 1, N + n, cmp);
	int l = 1, ans = 0;
	while (l <= n)
	{
		if (l == n)
			break;
		int tmp = l + 1, sum = N[l].num;
		while (N[l].minu == N[tmp].minu && tmp <= n)
		{
			sum += N[tmp].num;
			// cout << l << " " << tmp << endl;
			tmp++;
			ans = max(sum, ans);
		}
		// cout << ans << endl;
		l = tmp;
	}
	cout << ans << '\n';
}
signed main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int T = 1;
	cin >> T;
	while (T--)
	{
		solve();
	}
	return 0;
}