#include<iostream>
#include<stdio.h>
#include<algorithm>
#include<cstring>
#include<set>
#include<cmath>
#include<map>
#include<vector>
using namespace std;
#define int long long

inline int read()
{
    int x=0,f=1;
    char c=getchar();
    while(c<'0'||c>'9')
    {
       if(c=='-') f=-1;
        c=getchar();
    }
    while('0'<=c&&c<='9')
    {
       x=(x<<3) +(x<<1) +(c^48);
       c=getchar();
    }
    return x*f;
}

const int maxn = 100005;
int a[maxn];
vector<int> q[maxn];
map<int,int> mp;

signed main()
{
    int T=read();
    while(T--)
    {
        mp.clear();
        int n=read();
        int cnt=0;
        for(int i=1;i<=n;++i) a[i]=read();
        int temp;
        for(int i=1;i<=n;++i)
        {
            temp = a[i]-i;
            if( mp[temp]==0 ) mp[temp]=++cnt;
            temp = mp[temp];
            q[temp].push_back(a[i]);
        }

        int ans = 0;
        for(int i=1;i<=cnt;++i)
        {
            sort(q[i].begin(),q[i].end());
            int size = q[i].size();
            for(int j=size-1;j>=0;j-=2)
            {
                if(j<=0) break;
                if(q[i][j] + q[i][j-1] > 0 ) ans += q[i][j] + q[i][j-1];
            }
            q[i].clear();
        }
        printf("%lld\n",ans);
    }
    return 0;
}