#include <bits/stdc++.h>

using namespace std;

#define MAX 110000

int t, n, tree[MAX * 4];

pair<int, int> p[MAX];

void update(int v, int l, int r, int idx, int val)
{
	if(l > idx || r < idx)return ;
	if(l == r && r == idx)
	{
		tree[v] = val;
		return ;
	}
	int mid = (l + r) / 2;
	update(v * 2, l, mid, idx, val);
	update(v * 2 + 1, mid + 1, r, idx, val);
	tree[v] = max(tree[v * 2], tree[v * 2 + 1]);
	return ;
}

int query(int v, int l, int r, int idx)
{
	if(l > idx)return 0;
	if(r <= idx)return tree[v];
	int mid = (l + r) / 2;
	return max(query(v * 2, l, mid, idx), query(v * 2 + 1, mid + 1, r, idx));
}

void solve()
{
	int ans = 0, tmp = 0;
	scanf("%d", &n);
	for(int i = 1; i <= n; i++)
	{
		scanf("%d", &p[i].first);
		p[i].second = n - i;
	}
	for(int i = 0; i <= 4 * n; i++)tree[i] = 0;
	sort(p + 1, p + n + 1);
	for(int i = 1; i <= n; i++)p[i].second = n - p[i].second;
	for(int i = 1; i <= n; i++)
	{
		if(p[i].first == p[i + 1].first)
		{
			tmp = query(1, 1, n, p[i + 1].second);
			update(1, 1, n, p[i].second, max(tmp + 1, 1));
			ans = max(max(tmp + 1, 1), ans);
		}
		//cout << p[i].first << " " << p[i + 1].second << " " << ans << " " << query(1, 1, n, p[i + 1].second)<< endl;
	}
	cout << 2 * ans << endl;
	return ;
}

int main()
{
	freopen("stairway.in", "r", stdin);
	freopen("stairway.out", "w", stdout);
	cin >> t;
	for(int i = 1; i <= t; i++)solve();
	
	return 0;
}


/*

1
6
1 2 1 2 3 3

1
10
1 1 2 2 3 3 4 4 5 5

*/