// 
#include<bits/stdc++.h>
#define MAXN (1005)
#define MAXB (55)
#define MAXS (3005)
#define ll long long
using namespace std;
const int mod=1000000007,inv2=500000004,lim=1500,B=50;
void File()
{
    freopen(".in","r",stdin);
    freopen(".out","w",stdout);
}
template<typename type>
void read(type &x)
{
    bool f=0;char ch=0;x=0;
    while(ch<'0'||ch>'9'){f|=!(ch^'-');ch=getchar();}
    while(ch>='0'&&ch<='9'){x=(x<<3)+(x<<1)+(ch^48);ch=getchar();}
    x=f?-x:x;
}
template<typename type,typename... Args>
void read(type &x,Args &... args)
{
    read(x);
    read(args...);
}
inline int qpow(int x,int y)
{
    int res=1;
    while(y)
    {
        if(y&1) res=1ll*res*x%mod;
        x=1ll*x*x%mod,y>>=1;
    }
    return res; 
}
int n,ans=1;
int npw[MAXS],fac[MAXS],ifac[MAXS],a[MAXN],cnt[MAXB],f[MAXB][MAXS];
inline int C(int r,int k){return 1ll*fac[r]*ifac[k]%mod*ifac[r-k]%mod;}
inline int sgn(int x){return (x&1)?(mod-1):1;}
void init()
{
    fac[0]=1;
    for(int i=1;i<=lim;i++) fac[i]=1ll*fac[i-1]*i%mod;
    ifac[lim]=qpow(fac[lim],mod-2);
    for(int i=lim;i;i--) ifac[i-1]=1ll*ifac[i]*i%mod;
    npw[0]=1;
    for(int i=1;i<=lim;i++) npw[i]=1ll*npw[i-1]*inv2%mod;
}
int main()
{
#ifndef ONLINE_JUDGE
    File();
#endif
    init();
    read(n);
    for(int i=1;i<=n;i++)
    {
        read(a[i]);
        for(int j=0;j<a[i];j++) ++cnt[j];
    }
    for(int i=0;i<=n;i++)
    {
        for(int j=0;j<=i;j++)
            f[0][i]=(f[0][i]+1ll*sgn(j)*C(n,j)%mod*qpow(i-j,n))%mod;
        f[0][i]=1ll*f[0][i]*ifac[n]%mod;
    }
    for(int i=n;i;i--) f[0][i]=(f[0][i]-f[0][i-1]+mod)%mod;
    for(int i=0;i<=lim;i++) f[0][i]=f[0][i+1];
    for(int i=0;i<=B;i++)
        for(int j=0;j<=lim;j++)
            for(int k=0;k<=cnt[i];k++)
                f[i+1][j+k>>1]=(f[i+1][j+k>>1]+1ll*f[i][j]*C(cnt[i],k)%mod*npw[cnt[i]])%mod;
    for(int i=1,tr;i<=n;i++)
    {
        tr=f[a[i]][0];
        for(int j=a[i];j<=B;j++) tr=1ll*tr*npw[cnt[j]]%mod;
        ans=(ans-tr+mod)%mod;
    }
    printf("%d",ans);
}