#include <bits/stdc++.h>
using namespace std;
long long gcd(long long a, long long b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
long long lcm(long long a, long long b) { return (a * b) / gcd(a, b); }
void print(vector<long long> a) {
  for (int i = 0; i < a.size(); i++) {
    cout << a[i] << ' ';
  }
  cout << endl;
}
vector<long long> inp(int n) {
  vector<long long> a;
  long long x;
  for (int i = 0; i < n; i++) {
    cin >> x;
    a.push_back(x);
  }
  return a;
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long t, n, i, j, k, l, c, c1, cnt, flag, m2, maxi, mini, x, y, z;
  vector<long long> a, b;
  string s, s1, s2;
  map<long long, long long>::iterator itr;
  cin >> t;
  while (t--) {
    cin >> n;
    a = inp(n);
    map<long long, long long> m, m1;
    mini = INT_MAX;
    maxi = 0;
    for (i = 0; i < n; i++) {
      mini = min(mini, a[i]);
      maxi = max(maxi, a[i]);
      m[a[i]]++;
    }
    m1 = m;
    mini = mini * 2;
    maxi = maxi * 2;
    cnt = 0;
    for (i = mini; i <= maxi; i++) {
      m = m1;
      c = 0;
      for (itr = m.begin(); itr != m.end(); itr++) {
        if (itr->first < i) {
          x = i - itr->first;
          if (x == itr->first) {
            y = m[x] / 2;
            m[x] = m[x] - y * 2;
            c = c + y;
          } else {
            if (m.find(x) != m.end()) {
              y = min(itr->second, m[x]);
              itr->second = itr->second - y;
              m[x] = m[x] - y;
              c = c + y;
            }
          }
        }
      }
      cnt = max(cnt, c);
    }
    cout << cnt << endl;
    m.clear();
    m1.clear();
  }
}
