#include <bits/stdc++.h>

using namespace std;

const int maxn = 1e5 + 5;

int N, a[maxn], pre[maxn], vis[maxn];
long long Ans;
map<int, int> mp;
priority_queue<int> que;

void deal(int pos) {
  while (!que.empty()) que.pop();
  while(pos) vis[pos] = 1, que.push(a[pos]), pos = pre[pos];
  while (que.size() >= 2) {
    int x = que.top();
    que.pop();
    int y = que.top();
    que.pop();
    if (x + y <= 0) return;
    Ans += x + y;
  }
}

void solve() {
  cin >> N;
  mp.clear(), Ans = 0;
  for (int i = 1; i <= N; i++) cin >> a[i], vis[i] = 0;
  for (int i = 1; i <= N; i++) {
    if (!mp.count(a[i] - i)) {
      pre[i] = 0;
      mp[a[i] - i] = i;
    } else {
      pre[i] = mp[a[i] - i];
      mp[a[i] - i] = i;
    }
  }
  for (int i = N; i >= 1; i--) {
    if (vis[i]) continue;
    deal(i);
  }
  cout << Ans << endl;
}

int main() {
  //  freopen("a.in", "r", stdin);
  int T = 0;
  cin >> T;
  while(T--) solve();
  return 0;
}