#include <bits/stdc++.h>
#define ll long long
#define F first
#define S second
#define endl '\n'
#define Endl '\n'

using namespace std;

const int N = 2e5 + 5;
int tc, n, m, a[N];

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); // cout.tie(0);
    cin >> tc;
    while (tc--) {
        map<char, int> mp;
        string s;
        cin >> n >> s;
        for (auto i : s) {
            mp[i]++;
        }
        ll Ans = 0;
        for (auto i : mp) {
            ll cnt = i.S;
            Ans += (cnt * (cnt - 1));
        }
        cout << Ans << endl;
    }

    return 0;
}