#include <cstdio>
#include <algorithm>
#include <cstring>
using namespace std;

typedef long long ll;

int n, m;

ll cal(ll x) {
    return x * (x + 1) / 2;
}

int main() {
    int T;
    scanf("%d", &T);
    while (T--) {
        scanf("%d%d", &n, &m);
        if (m >= n / 2) printf("%lld\n", cal(n - 1));
        else {
            ll ans = cal(n - 1) - cal(n - 1 - m) + cal(m - 1);
            ans += 1LL * (n - m * 2) * m;
            printf("%lld\n", ans);
        }
    }
    return 0;
}