#include<bits/stdc++.h>
#define ll long long 
using namespace std;

int main(){
  int t;
  cin >> t;
  while (t--){
    ll n, ans = 0;
    string s;
    vector<ll> a(26);
    cin >> n >> s;
    for (int i = 0; i < n; i++){
      a[s[i] - 97]++;
    }
    for (int i = 0; i < 26; i++){
      ans += (a[i] * (a[i] - 1));
    }
    cout << ans << endl;
  }
}