#include <bits/stdc++.h>

#ifdef LOCAL
#include "../algo/debug.h"
#else 
#define debug(...) 0
#endif

using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int tt;
  cin >> tt;
  while (tt--) {
    int n; string s;
    cin >> n >> s;
    vector<int> a(26);
    for (char c : s) a[c - 'a'] += 1;
    long long ans = 0;
    for (int i = 0; i < 26; i++) ans += a[i] * 1ll * (a[i] - 1);
    cout << ans << '\n';
  }
  return 0;
}