73

#include <bits/stdc++.h>
using namespace std;


int n, res, a[51];
vector<pair<long long, int>> d[101];


void query(){
    cin >> n; res = 1;
    for (int i = 1; i <= n; ++i)
        cin >> a[i],
        d[i].clear();
    for (int i = n + 1; i <= 2*n; ++i)
        d[i].clear();
    for (long long i = 1; i < n; ++i)
        for (long long j = i + 1; j <= n; ++j) {
            int sum = a[i] + a[j];
            long long f = ((1 << i) | (1 << j));
            int s = d[sum].size();
            for (int k = 0; k < s; ++k)
                if (!(d[sum][k].first & f))
                    res = max(res, d[sum][k].second + 1),
                    d[sum].push_back({d[sum][k].first | f, d[sum][k].second + 1});
            d[sum].push_back({f, 1});
        }
    cout << res << '\n';
}

int main(){
    //freopen("FILENAME.INP", "r", stdin);
    //freopen("FILENAME.OUT", "w", stdout);


    int t;
    for (cin >> t; t--;)
        query();


    return 0;
}