// Author: Klay Thompson
// Problem: G. Matching
// Memory Limit: 1024 MB
// Time Limit: 1000 ms
// 
// Powered by CP Editor (https://cpeditor.org)

#include <bits/stdc++.h>

#define rep(i, j, k) for (int i = (j); i <= (k); ++i)
#define per(i, j, k) for (int i = (j); i >= (k); --i)
#define SZ(v) int((v).size())
#define ALL(v) (v).begin(),(v).end()
#define fi first
#define se second
using ll = long long;
using pii = std::pair<int, int>;
using pll = std::pair<ll, ll>;

template<class T>inline void chkmn(T &x, T y) { if (y < x) x = y; }
template<class T>inline void chkmx(T &x, T y) { if (y > x) x = y; }

using namespace std;

const int maxn = 100010;

int n, a[maxn];
pii w[maxn];

void work() {
  cin >> n;
  rep (i, 1, n) cin >> a[i];
  rep (i, 1, n) w[i] = pii(a[i] - i, a[i]);
  sort(w + 1, w + n + 1);
  ll ans = 0;
  for (int l = 1, r; l <= n; l = r + 1) {
    r = l;
    while (r < n && w[r + 1].fi == w[r].fi) r++;
    if ((r - l + 1) & 1) l++;
    reverse(w + l, w + r + 1);
    ll mx = 0, sum = 0;
    for (int i = l + 1; i <= r; i += 2) {
      sum += w[i - 1].se + w[i].se;
      chkmx(mx, sum);
    }
    ans += mx;
  }
  cout << ans << '\n';
}

int main() {
  cin.tie(nullptr) -> ios::sync_with_stdio(false);
  int t; cin >> t;
  while (t--) work();
}