#include <bits/stdc++.h>
#include <sys/types.h>
#include <stdio.h>
#include <unistd.h>
#define _USE_MATH_DEFINES
#define ll long long int
#ifndef ONLINE_JUDGE
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif
using namespace std;
//mp.reserve(1024);
//mp.max_load_factor(0.25);
void __print(int x) {cerr << x;}
void __print(long x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(unsigned x) {cerr << x;}
void __print(unsigned long x) {cerr << x;}
void __print(unsigned long long x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}
 
template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
vector<ll> v(200001);
ll dp[200001];
ll cal(ll x, ll n){
	if(x>=n)
		return 0;
	ll now = v[x];
	if(dp[x]!=-1)
		return dp[x];
	ll val = now;
	if(x+v[x]<n){
		val += cal(x+v[x], n);
	}
	dp[x] = val;
	return dp[x];
	
}
int main()
{
	ios_base::sync_with_stdio(false);
   	cin.tie(NULL);
   	cout.tie(NULL);
    //freopen("input.txt", "r", stdin);
    //freopen("output1.txt", "w", stdout);
	ll t;
	cin>>t;
	while(t--){
		ll n, ans = INT_MIN;
		cin>>n;
		memset(dp, -1, sizeof dp);
		for(ll i=0;i<n;i++){
			cin>>v[i];
		}
		for(ll i=0;i<n;i++){
			ans = max(ans ,cal(i, n));
		}
		cout<<ans<<endl;
	}
	return 0;
}










