#include<iostream>
using namespace std;
int main()
{
	long long a;
	long long n, k;
	cin >> a;
	for (int i = 1; i <= a; i++)
	{
		cin >> n >> k;
		int sdjhsajdsajhsa = (1 + k) * k / 2;
		if (n == sdjhsajdsajhsa)
		{
			cout << "YES" << endl;
		}
		else
		{
			cout << "NO" << endl;
		}
	}
	return 0;
}