#include<iostream>
#include<string.h>
#include<stdio.h>
#include<iomanip>
#include <stdlib.h>
#include<algorithm>
using namespace std;
int main()
{
    int test;
    cin>>test;
    while(test--)
    {
        long long n,m,x,sum=0;
        cin>>n>>m;
        if(n==1||m==0)cout<<0<<endl;
        else{
            x=n/2;
            if(m>=x){
                sum=(n-1)*n/2;
            }
            else{
                sum=(n-m+n-1)*m/2;
                sum+=m*(n-2*m);
                sum+=(m-1)*m/2;
            }
            cout<<sum<<endl;
        }
    }
    return 0;
}