# include <cstdio>
# include <iostream>
# include <algorithm>
using namespace std;
const int maxn = 30 + 5;
int a[maxn];
typedef long long ll;

ll C(int n, int k) {
    if(k == 0) return 1;
    ll r = 1;
    for(int i = n, j = k; i > n - k || j >= 1; i--, j--) {
        if(i > n - k) r *= i;
        if(j >= 1 && r % j == 0) r /= j;
        else j++;
    }
    return r;
}

int main(void)
{
    int T, n;
    scanf("%d", &T);
    while (T--) {
        ll even = 0, odd = 0;
        scanf("%d", &n);
        for (int i = 0; i < n; ++i)
            scanf("%d", a + i);
        sort(a, a + n);
//        if (n % 2 == 0) even += a[0];
        for (int i = 0; i < n; ++i) {
//            even += (n - 1 - i) * a[i];
            int t = n - 1 - i, cnt = 0;

            for (int j = 1; j <= t; j += 2)
                cnt += C(t, j);
            even += cnt * a[i];
            cnt = 0;
            for (int j = 0; j <= t; j += 2)
                cnt += C(t, j);
            odd += cnt * a[i];
//            printf("even = %d, odd = %d\n", even, odd);
        }
        ll cha = even - odd;
        if (cha < 0) cha = -cha;
        printf("%lld\n", cha);
    }

    return 0;
}