from collections import Counter, defaultdict
for _ in range(int(input())):
n = int(input())
cnt = Counter([int(i) for i in input().split()])
d = [0] * 110
for i in cnt :
for j in cnt : d[i+j] += min(cnt[i], cnt[j])
print(max(d)//2) #include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <queue>
#include <algorithm>
#include <deque>
#include <cstring>
using namespace std;
const int N=2e5+10,INF=0x3f3f3f3f,mod=1e9+7;
typedef pair<int,int>PII;
typedef long long LL;
int a[N];
int st[N];
void solve()
{
int n;
cin>>n;
for(int i=1;i<=n;i++)cin>>a[i];
int ans=0;
for(int s=1;s<=100;s++)
{
int res=0;
for(int i=1;i<=n;i++)st[i]=0;
for(int i=1;i<n;i++)
{
for(int j=i+1;j<=n;j++)
{
if(a[i]+a[j]==s&&!st[i]&&!st[j])
{
res++;
st[i]=st[j]=true;
break;
}
}
}
ans=max(ans,res);
}
cout<<ans<<'\n';
}
signed main()
{
int T=1;
cin>>T;
while(T--)solve();
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