#include <bits/stdc++.h>

#pragma GCC optimize("Ofast")
using namespace std;

void solve(int cs) {
  int n;
  cin >> n;
  string s;
  cin >> s;
  array<int, 26> cnt{};
  for (auto c : s) cnt[c - 'a'] += 1;
  int64_t res = 0;
  for (auto i : cnt) {
    res = res + (i * 1LL * (i - 1));
  }
  cout << res << "\n";
}

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int tc = 1;
  cin >> tc;
  for (int cs = 1; cs <= tc; cs++) {
    solve(cs);
  }
  return 0;
}