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

#define ll unsigned long long
#define endl '\n'

void solve(int cs){
    int n;cin>>n;
    string s;
    cin>>s;
    
    int arr[30] = {0};
    for(int i = 0; i < n; i++){
        arr[s[i] - 'a'+1]++;
    }
    ll ans = 0;
	bool f = 0;
    for(int i = 1; i < 30; i++){
        //cout<<arr[i]<<" ";
        if(arr[i]>1){
			ans += (arr[i] * (arr[i]-1));
			f = 1;
		}
    }
    cout<<(ans)<<endl;

}
   
int main()
{

    ios_base::sync_with_stdio(false);cin.tie(0);
    int t=1,cs=0;
    cin >> t;
    while(t--)
    {
        solve(++cs);
    }

    return 0;
}