#include<bits/stdc++.h>
using namespace std;
#define int long long
const int MAXN = 1e6 + 10;
int N,M,K,Q;
int a[MAXN];

int tot = 0;
map<int,int> mp;

int get(int x){
    if(int ret = mp[x]) return ret;
    return mp[x] = ++tot;
}

pair<int,int> b[MAXN];

void prepare(){
    scanf("%lld",&N);
    for(int i = 1;i <= N; i++) scanf("%lld",&a[i]);
    for(int i = 1;i <= N; i++){
        b[i].first = a[i] - i;
        b[i].second = -a[i];
    }
    sort(b+1,b+1+N);
    int ans = 0;
    for(int i = 1;i <= N; i++){
        if(b[i].first == b[i+1].first){
            if(b[i].second + b[i+1].second <= 0) ans -= b[i].second + b[i+1].second;
            i++;
        }
    }
    printf("%lld\n",ans);
}

signed main(){
    int T = 1;
    scanf("%lld",&T);
    while(T--){
        prepare();
    }
}