#include <bits/stdc++.h>
 
using namespace std;
 
const int MaxN = (int)1e5 + 10;
const int INF = (int)1e9;
const int MOD = (int)1e9 + 7;

int a[MaxN];
int cnt[2018];

void solve() {
	int n;
	scanf("%d", &n);
	assert (1 <= n && n <= 100000);
	memset(cnt, 0, sizeof(cnt));
	for (int i = 1; i <= n; ++i) {
		scanf("%d", &a[i]);
		assert (abs(a[i]) <= 1000);
		a[i] += 1000;
		cnt[a[i]] += 1;
	}
	long long ans = 0;
	for (int mid = 0; mid <= 2000; ++mid) {
		if (!cnt[mid]) {
			continue;
		}
		ans += 1LL * cnt[mid] * (cnt[mid] - 1) / 2;
		for (int x = 1; mid - x >= 0 && mid + x <= 2000; ++x) {
			ans += 1LL * cnt[mid - x] * cnt[mid + x];
		}
	}
	printf("%lld\n", ans);
}

int main() {
//	freopen("input.txt", "r", stdin);
	int t;
	scanf("%d", &t);
	assert (1 <= t && t <= 10);
	while (t --> 0) {
		solve();
	}
	return 0;
}