import java.util.ArrayList;
import java.util.Random;
import java.util.Scanner;

public class Solution {
	Scanner in = new Scanner(System.in);
	int comparison = 0;
	public static void main(String[] args) {
		new Solution().solve();
	}

	void solve() {
		int t = in.nextInt();
		for (int T=0; T < t; T++) {
			int n = in.nextInt();
			int c =  in.nextInt();
			int max = 0;
			for (int i = 1; i < n; i++) {
				max += i;

			}
			int min = calculateMin(n);
			//System.out.printf("Min = %d\n",min);
			//min = n-1;
			if ((c > max) || (c < min)){
				System.out.println(-1);
			}else {
				if (( c == min) && (c == max)) {
					//can only be n=1
					System.out.println(1);
				}else {
					Integer[] a = new Integer[n];
					for (int i = 1; i <= n; i++) {
						a[i-1]= i;
					}
					
					while (comparison != c){
						comparison = 0;
						shuffleArray(a);
						lena_sort(a);
						//			System.out.println(comparison);
						if (comparison == c) {
							for (int i=0; i < n; i++) {
								System.out.printf("%d ", a[i]);
							}
							System.out.println();
						}
					}
				}
			}
		}
	}
	private int calculateMin(int n) {
		if (n==1) return 0;
		if (n==0) return 0;
		if (n==2) return 1;
		int times = (n-1) /2;
		return (n-1) + (times * calculateMin(n/2));
	}

	void shuffleArray(Integer[] ar)
	{
		// If running on Java 6 or older, use `new Random()` on RHS here
		Random rnd = new Random();
		for (int i = ar.length - 1; i > 0; i--)
		{
			int index = rnd.nextInt(i + 1);
			// Simple swap
			int a = ar[index];
			ar[index] = ar[i];
			ar[i] = a;
		}
	}
	Integer[] lena_sort(Integer[]  nums) {
		if (nums.length <= 1) {
			return nums;
		}
		int pivot = nums[0];
		ArrayList<Integer> less = new ArrayList<Integer>();
		ArrayList<Integer> more = new ArrayList<Integer>();

		for (int i = 1; i < nums.length; ++i) {
			// Comparison
			comparison++;
			if (nums[i] < pivot) {
				less.add(nums[i]);
			}
			else {
				more.add(nums[i]);
			}
		}

		Integer []sorted_less_param = new Integer[less.size()];
		sorted_less_param = less.toArray(sorted_less_param);
		Integer []sorted_less= lena_sort(sorted_less_param);
		Integer []sorted_more_param = new Integer[more.size()];
		sorted_more_param = more.toArray(sorted_more_param);
		Integer []sorted_more =  lena_sort(sorted_more_param);

		Integer [] ans = new Integer[sorted_less.length + sorted_more.length +1];

		for (int i = 0; i < sorted_less.length; i++) {
			ans[i] = sorted_less[i];
		}
		ans[sorted_less.length] = pivot;

		int j = sorted_less.length + 1;
		int i = 0;
		for (; j< ans.length; j++) {
			ans[j] = sorted_more[i];
			i++;
		}

		return ans;
	}
}