/*
 *   Copyright (c) 2024 Emon Thakur
 *   All rights reserved.
 */
#include<bits/stdc++.h>
using namespace std;
using ll=long long;

//ofstream file("output0.txt");
void solve()
{
    int n; cin>>n;
    string s; cin>>s;
    ll a[26]={0};
    for(int i=0;i<n;i++) a[s[i]-'a']++;
    ll ans=0;
    for(int i=0;i<26;i++) ans += (a[i]*(a[i]-1));
    cout<<ans<<endl;
    //file<<ans<<endl;
}
int main()
{
    //freopen("input0.txt","r",stdin);
    int t; cin>>t; while(t--) solve();
}