#include <bits/stdc++.h>
#define rep(i, a, b) for (int i = a; i <= b; i++)
#define per(i, a, b) for (int i = a; i >= b; i--)
using namespace std;

typedef unsigned long long ull;
typedef pair <int, int> pii;
typedef long long ll;

template <typename _T>
inline void read(_T &f) {
    f = 0; _T fu = 1; char c = getchar();
    while (c < '0' || c > '9') { if (c == '-') { fu = -1; } c = getchar(); }
    while (c >= '0' && c <= '9') { f = (f << 3) + (f << 1) + (c & 15); c = getchar(); }
    f *= fu;
}

template <typename T>
void print(T x) {
    if (x < 0) putchar('-'), x = -x;
    if (x < 10) putchar(x + 48);
    else print(x / 10), putchar(x % 10 + 48);
}

template <typename T>
void print(T x, char t) {
    print(x); putchar(t);
}

const int md = 1e9 + 7, inv2 = (md + 1) / 2;

inline int add(int x, int y) {
    if (x + y >= md) return x + y - md;
    return x + y;
}

inline void addx(int &x, int y) {
    x += y;
    if (x >= md) x -= md;
}

inline int sub(int x, int y) {
    if (x < y) return x - y + md;
    return x - y;
}

inline void subx(int &x, int y) {
    x -= y;
    if (x < 0) x += md;
}

inline int mul(int x, int y) { return 1ull * x * y % md; }

inline int fpow(int x, int y) {
    int ans = 1;
    while (y) {
        if (y & 1) ans = mul(ans, x);
        y >>= 1; x = mul(x, x);
    }
    return ans;
}

const int N = 2005, M = 55;

int a[N], dp[N], ndp[N], cc[M], cnt[M], C[N][N], pw[N];
int n, ans;

int main() {
    read(n);
    pw[0] = 1;
    for (int i = 1; i <= n; i++) pw[i] = mul(pw[i - 1], inv2);
    C[0][0] = 1;
    for (int i = 1; i <= n; i++) {
        C[i][0] = 1;
        for (int j = 1; j <= i; j++) C[i][j] = add(C[i - 1][j - 1], C[i - 1][j]);
    }
    for (int i = 1; i <= n; i++) {
        read(a[i]);
        for (int j = 0; j < a[i]; j++) ++cnt[j];
        ++cc[a[i]];
    }
    for (int i = 50; i >= 0; i--) {
        for (int j = n * 2; j >= 0; j--) {
            if (j & 1) dp[j] = 0;
            else dp[j] = dp[j / 2];
        }
        memset(ndp, 0, sizeof(ndp));
        for (int j = 0; j <= n * 2; j++) {
            if (!dp[j]) continue;
            int tmp = mul(dp[j], pw[cnt[i]]);
            for (int k = 0; k <= min(cnt[i], j + 1); k++) {
                ndp[j + 1 - k] = add(ndp[j + 1 - k], mul(C[cnt[i]][k], tmp));
            }
        }
        for (int j = n + 1; j <= n * 2 + 1; j++) ans = add(ans, ndp[j]);
        for (int j = 0; j <= n; j++) dp[j] = ndp[j];
        int p = 1;
        for (int j = i; j <= 50; j++) p = mul(p, fpow(inv2, cnt[j]));
        dp[0] = add(dp[0], mul(p, cc[i]));
    }
    // for (int i = 0; i <= n; i++) fprintf(stderr, "dp[%d] = %d\n", i, dp[i]);
    int coef = n;
    for (int i = 1; i <= n - 1; i++) coef = mul(coef, i);
    coef = fpow(coef, md - 2);
    for (int i = 0; i <= n; i++) {
        int x = i + 1, sum = 0;
        for (int k = 0; k < x; k++) {
            int res = mul(C[n][k], fpow(x - k, n));
            if (k & 1) sum = sub(sum, res);
            else sum = add(sum, res);
        }
        sum = mul(sum, coef);
        // fprintf(stderr, "x = %d, sum = %d\n", x, sum);
        ans = add(ans, mul(sum, dp[i]));
    }
    ans = sub(1, ans);
    print(ans, '\n');
    return 0;
}