#include<bits/stdc++.h>
#define Yukinoshita namespace
#define Yukino std
#define int long long
using Yukinoshita Yukino;
int read()
{
	int s=0,w=1;
	char ch=getchar();
	while(ch<'0'||ch>'9') w=ch=='-'?-1:1,ch=getchar();
	while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
	return s*w;
}
const int mxn=1e5+5;
vector<int> qwq[mxn];
signed main()
{
	int T=read();
	while(T--)
	{
		map<int,int> mp;
		int n=read(),i;
		for(i=1;i<=n;i++)
			qwq[i].clear();
		for(i=1;i<=n;i++)
		{
			int x=read();
			if(!mp[x-i]) mp[x-i]=i;
			qwq[mp[x-i]].push_back(x);
		}
		int s=0;
		for(i=1;i<=n;i++)
		{
			sort(qwq[i].begin(),qwq[i].end());
			reverse(qwq[i].begin(),qwq[i].end());
			for(int j=0;j+1<qwq[i].size();j+=2)
				if(qwq[i][j]+qwq[i][j+1]>0)
					s+=qwq[i][j]+qwq[i][j+1];
		}
		printf("%lld\n",s);
	}
	
}