#include <bits/stdc++.h>
using namespace std;

#define ms(s, n) memset(s, n, sizeof(s))
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define FORd(i, a, b) for (int i = (a) - 1; i >= (b); i--)
#define FORall(it, a) for (__typeof((a).begin()) it = (a).begin(); it != (a).end(); it++)
#define FORalld(it, a) for (__typeof((a).rbegin()) it = (a).rbegin(); it != (a).rend(); it++)
#define sz(a) int((a).size())
#define present(t, x) (t.find(x) != t.end())
#define all(a) (a).begin(), (a).end()
#define uni(a) (a).erase(unique(all(a)), (a).end())
#define pb push_back
#define pf push_front
#define mp make_pair
#define fi first
#define se second
#define prec(n) fixed<<setprecision(n)
#define bit(n, i) (((n) >> (i)) & 1)
#define bitcount(n) __builtin_popcountll(n)
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pi;
typedef vector<int> vi;
typedef vector<pi> vii;
const int MOD = (int) 1e9 + 7;
const int INF = (int) 1e9;
const ll LINF = (ll) 1e18;
const ld PI = acos((ld) -1);
const ld EPS = 1e-9;
inline ll gcd(ll a, ll b) {ll r; while (b) {r = a % b; a = b; b = r;} return a;}
inline ll lcm(ll a, ll b) {return a / gcd(a, b) * b;}
inline ll fpow(ll n, ll k, int p = MOD) {ll r = 1; for (; k; k >>= 1) {if (k & 1) r = r * n % p; n = n * n % p;} return r;}
template<class T> inline int chkmin(T& a, const T& val) {return val < a ? a = val, 1 : 0;}
template<class T> inline int chkmax(T& a, const T& val) {return a < val ? a = val, 1 : 0;}
template<class T> inline T isqrt(T k) {T r = sqrt(k) + 1; while (r * r > k) r--; return r;}
template<class T> inline T icbrt(T k) {T r = cbrt(k) + 1; while (r * r * r > k) r--; return r;}
inline void addmod(int& a, int val, int p = MOD) {if ((a = (a + val)) >= p) a -= p;}
inline void submod(int& a, int val, int p = MOD) {if ((a = (a - val)) < 0) a += p;}
inline int mult(int a, int b, int p = MOD) {return (ll) a * b % p;}
inline int inv(int a, int p = MOD) {return fpow(a, p - 2, p);}
inline int sign(ld x) {return x < -EPS ? -1 : x > +EPS;}
inline int sign(ld x, ld y) {return sign(x - y);}

const int MAXN = 100000 + 5;
const int LOGN = 20;
int tr[LOGN + 1][MAXN];
long long sm[LOGN + 1][MAXN];
void insert(int x, int t) {
	for (int i = 0; i < LOGN; i++) {
		tr[i][x]++;
		sm[i][x] += t;
		x >>= 1;
	}
}
void erase(int x, int t) {
	for (int i = 0; i < LOGN; i++) {
		tr[i][x]--;
		sm[i][x] -= t;
		x >>= 1;
	}
}
int kthelm(int k) {
	int res = 0;
	int a = 0, b = LOGN;
	while (b--) {
		a <<= 1;
		k -= tr[b][a] < k ? tr[b][a++] : 0;
		res = sm[b][a] / tr[b][a];
	}
	return res;
}

const int maxn = 100000 + 5;
int a[maxn];

void solve() {
	int q; cin >> q;
	while (q--) {
		long long n, c; cin >> n >> c;
		if (c > n * (n - 1) / 2) {
			cout << -1 << "\n";
			continue;
		}
		c = n * (n - 1) / 2 - c;
		FOR(i, 1, n + 1) insert(i, i);
		priority_queue<pi> que; que.push(mp(-0, n - 1));
		while (sz(que)) {
			int ix = -que.top().fi;
			long long m = que.top().se;
			que.pop();
			long long l = 0, r = m >> 1;
			while (l < r) {
				long long mid = l + r + 1 >> 1;
				long long zzz = m - mid;
				if (m * (m - 1) / 2 - mid * (mid - 1) / 2 - zzz * (zzz - 1) / 2 <= c) {
					l = mid;
				}
				else {
					r = mid - 1;
				}
			}
			long long mid = l, zzz = m - mid;
			if (mid > 0) {
				que.push(mp(-(ix + 1), mid - 1));
			}
			if (zzz > 0) {
				que.push(mp(-(ix + mid + 1), zzz - 1));
			}
			c -= m * (m - 1) / 2 - mid * (mid - 1) / 2 - zzz * (zzz - 1) / 2;
			a[ix] = kthelm(mid + 1);
			erase(a[ix], a[ix]);
		}
		if (c) {
			cout << -1 << "\n";
			continue;
		}
		FOR(i, 0, n) cout << a[i] << " \n"[i == n - 1];
	}
}

int main() {
#ifdef _LOCAL_
	freopen("in.txt", "r", stdin); //freopen("out.txt", "w", stdout);
#else
	ios_base::sync_with_stdio(0); cin.tie(0);
#endif
	solve();
#ifdef _LOCAL_
	//printf("\nTime elapsed: %dms", 1000 * clock() / CLOCKS_PER_SEC);
#endif
	return 0;
}