#include <cstdio>
using namespace std;
typedef long long ll;
ll n,m;
int main(){
    int t;scanf("%d",&t);
    while(t--){
        scanf("%lld%lld",&n,&m);
        ll ans = 0;
        if(m >= n/2) ans = (n-1)*n/2;
        else{
            if(m == 1) ans += (n - 1);
            else ans += (m * (n - 1 + n - m) / 2);
            ans += (n - 2ll*m)*m;
            ans += m * (m - 1)/2;
        }
        printf("%lld\n",ans);
    }
    return 0;
}