#include <bits/stdc++.h>
using namespace std;
template <typename Arg1>
void __f(const char* name, Arg1&& arg1) {
  cerr << name << " : " << arg1 << '\n';
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args) {
  const char* comma = strchr(names + 1, ',');
  cerr.write(names, comma - names) << " : " << arg1 << " | ";
  __f(comma + 1, args...);
}
int inf = 0x3f3f3f3f;
long long infl = 0x3f3f3f3f3f3f3f3fLL;
long double infd = 1.0 / 0.0;
const long long MOD = 1e9 + 7;
const double pi = 2 * acos(0.0);
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  int tt = 1;
  cin >> tt;
  while (tt--) {
    long long n, m;
    cin >> n >> m;
    long long as = ((n) * (n + 1)) / 2;
    if (m == 0) {
      cout << 0 << '\n';
      continue;
    }
    long long x = min(n - m, m);
    long long z = max(1ll * 0, n - m - x);
    as -= (x);
    as -= (z) * (z + 1) / 2;
    cout << as << '\n';
  }
  return 0;
}
