#include <bits/stdc++.h>

//DEBUG:    https://github.com/sharkdp/dbg-macro

//#include "../dbg-macro-0.5.1/dbg.h"


#define endl '\n'
using namespace std;
typedef long long ll;
const ll MAXN=2e5+10,MOD=1e9+7,INF=1e9;

ll qpow(ll base,ll exp){ll ans=1;while(exp){if(exp&1)(ans*=base)%=MOD;(base*=base)%=MOD;exp>>=1;}return ans;}
template<class T>ll max_binary_answer(ll l,ll r,T check,bool cmp=true){ll m;while(l<r){m=(l+r+1)/2;if(cmp^!check(m))l=m;else r=m-1;}return l;}
template<class T>ll min_binary_answer(ll l,ll r,T check,bool cmp=true){ll m;while(l<r){m=(l+r)/2;if(cmp^!check(m))r=m;else l=m+1;}return r;}
ll exgcd(ll a,ll b,ll &x,ll &y){ll tmp;return b==0?(x=1,y=0,a):(tmp=exgcd(b,a%b,y,x),y-=(a/b)*x,tmp);}
ll highbit(ll x){for(ll i=1;i<(ll)sizeof(ll)*4;i<<=1)x|=x>>i;return x-(x>>1);}
ll lowbit(ll x){return x&(-x);}
//--------Global declared area--------

//--------Global declared end --------
void solve(int test_num){
	int n;
	ll ans=0;
	cin>>n;
	vector<ll> a(n+1,-1e9);
	for(int i=1;i<=n;i++){
		cin>>a[i];
	}
	map<ll,ll> m;
	for(int i=n;i>=1;i--){
		if(m[a[i]-i]==0){
			m[a[i]-i]=i;
		}else if(a[i]+a[m[a[i]-i]]>0){
			ans+=a[i]+a[m[a[i]-i]];
			m[a[i]-i]=0;
		}
		
	}
	cout<<ans<<endl;
	return;
}

int main(){
	std::ios::sync_with_stdio(false);
	std::cin.tie(nullptr),std::cout.tie(nullptr);
	int t=1;
	cin>>t;
	for(int i=1;i<=t;i++){
		solve(i);
		//cout.flush();
	}
	return 0;
}