#include <bits/stdc++.h>

using namespace std;


int main()
{
    int t;
    long long n,m;
    scanf("%d",&t);
    while(t--)
    {
        scanf("%lld%lld",&n,&m);
        long long ans = -1;
        if(m>=n/2)
            ans = n*(n-1)/2;
        else
            ans = (n-2*m)*m*2 + m*(2*m-1);
        printf("%lld\n",ans);
    }
}