#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pii pair<int, int>
#define inf 0x3f3f3f3f
#define db double
#define il inline
#define x first
#define y second
#define endl '\n'
const int N = 2e5 + 5;
const int mod = 998244353;
int a[N];
void solve()
{
    int n;
    cin >> n;
    map<int, vector<int>> mp;
    for (int i = 1; i <= n; i++) 
    {
        cin >> a[i];
        mp[a[i] - i].push_back(i);
    }
    int ans = 0;
    for (auto [x, v]: mp)
    {
        sort(v.begin(), v.end());
        int sz = v.size();
        for (int i = sz - 1; i >= 1; i -= 2)
        {
            if (a[v[i]] + a[v[i - 1]] > 0) ans += a[v[i]] + a[v[i - 1]];
        }
    }
    cout << ans << '\n';
}
signed main()
{
    // freopen("D:\\3022244240\\vscode\\txt\\in.txt", "r", stdin);
    // freopen("D:\\3022244240\\vscode\\txt\\out.txt", "w", stdout);
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    int T = 1;
    cin >> T;
    while (T--) solve();
    return 0;
}

/*
3
9
3 -5 5 6 7 -1 9 1 2
3
-5 -4 -3
3
1 10 100
*/