#include <iostream>
using namespace std;
long long sum[1000010];
int main(){
    int T,n,m;
    for(int i=1;i<=1000000;++i) sum[i]=sum[i-1]+i;
    cin>>T;
    while(T--){
        cin>>n>>m;
        if(n/2<m) m=n/2;
        cout<<sum[n-1]-sum[n-2*m-1]<<endl;
    }
    return 0;
}