#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
void solve()
{
    int n;
    cin >> n;
    vector<ll> a(n + 1);
    unordered_map<ll, ll> mp;
    for(int i = 1; i <= n; i++)
    {
        cin >> a[i];
    }
    ll ans = 0;
    for(int i = n; i; i--)
    {
        ll x = a[i] - i;
        if(mp.count(x))
        {
            if(mp[x] + a[i] > 0)
            {
                ans += mp[x] + a[i];
            }
            mp.erase(x);
        }
        else mp[x] = a[i];
    }
    cout << ans << "\n";
}
int main()
{
    cin.tie(0)->sync_with_stdio(false);
    int T;
    cin >> T;
    while(T--) solve();
    return 0;
}