#include<bits/stdc++.h>
#define int long long
using namespace std;
int T,n,tot = 0;
int a[100010],b[100010];
vector<int>to[100010];
map<int,int>mp;
signed main(){
	scanf("%lld",&T);
	while(T--){
		mp.clear();
		tot = 0;
		scanf("%lld",&n);
		for(int i = 1; i <= n; i++){
			scanf("%lld",&a[i]),b[i] = a[i] - i;
			if(!mp[b[i]]) mp[b[i]] = ++tot;
			to[mp[b[i]]].push_back(i);
		} 
		int sum = 0;
		for(int v = 1; v <= tot; v++){
			for(int i = to[v].size() - 1; i >= 1; i -= 2){
				int val = a[to[v][i]] + a[to[v][i - 1]];
				if(val > 0) sum += val;
			}
			to[v].clear();
		}
		printf("%lld\n",sum);
	}
	return 0;
}