#include<bits/stdc++.h>
using namespace std;
#define rep(i,x,y) for (int i=(x);i<=(y);i++)
#define drep(i,y,x) for (int i=(y);i>=(x);i--)
#define pii pair<int,int>
template<typename T> bool chkmin(T &x, T y){return x>y?x=y,1:0;}
template<typename T> bool chkmax(T &x, T y){return x<y?x=y,1:0;}
void file() {
    #ifdef zqj
    freopen("a.in","r",stdin);
    #endif
}
typedef long long ll;
#define sz 1010
const ll mod=1000000007;
ll ksm(ll x,int y){ll res=1;for (;y;y>>=1,x=x*x%mod) if (y&1) res=res*x%mod;return res;}
ll inv(ll x){return ksm(x,mod-2);}

ll C[sz][sz],fac[sz];
ll I2[sz];
void init() {
    I2[0]=1,I2[1]=(mod+1)/2; rep(i,2,sz-1) I2[i]=I2[i-1]*I2[1]%mod;
    rep(i,0,sz-1) C[i][0]=1;
    rep(i,1,sz-1) rep(j,1,sz-1) (C[i][j]=C[i-1][j]+C[i-1][j-1])%=mod;
    fac[0]=1; rep(i,1,sz-1) fac[i]=fac[i-1]*i%mod;
}

ll calc(int n,int K) {
    ll ans=0;
    rep(i,0,K) ans+=((i&1)?mod-1:1)*C[n+1][i]%mod*ksm(K+1-i,n+1)%mod;
    return ans%mod*inv(fac[n+1])%mod;
}

int n;
int cc[sz],pp[sz];

ll dp[55][sz];

struct hh {
    vector<ll>dp;
    ll tot;
    hh(){tot=0;}
};

hh work(hh dp, int i, int type) {
    hh dp2; dp2.tot=dp.tot; dp2.dp=vector<ll>(n+1);
    rep(j,0,n) if (dp.dp[j]) rep(k,0,type) rep(l,0,pp[i]) {
        int x=2*j+k-l;
        ll w=dp.dp[j]*C[pp[i]-type][l]%mod*I2[pp[i]]%mod;
        if (x>n) (dp2.tot+=w)%=mod;
        else if (x>=0) (dp2.dp[x]+=w)%=mod;
    }
    return dp2;
}

int main() {
    file();
    ios::sync_with_stdio(false),cin.tie(0);
    init();
    cin>>n;
    int x;
    rep(i,1,n) cin>>x,++cc[x];
    drep(i,50,0) pp[i]=cc[i+1]+pp[i+1];



    hh dp0,dp1;
    dp0.dp=dp1.dp=vector<ll>(n+1);
    dp0.dp[0]=1;
    drep(i,50,0) {
        dp0=work(dp0,i,0);
        if (pp[i]) dp1=work(dp1,i,1);
        (dp1.tot+=dp0.tot*cc[i]%mod)%=mod;
        rep(k,0,n) (dp1.dp[k]+=dp0.dp[k]*cc[i]%mod)%=mod;
    }
    ll ans=1;
    rep(k,0,n) (ans+=mod-calc(n-1,k)*dp1.dp[k]%mod)%=mod;
    (ans+=mod-dp1.tot)%=mod;

    // rep(t,0,50) if (cc[t]) {
        // memset(dp,0,sizeof(dp));
        // dp[51][0]=1;
        // ll tot=0;
        // drep(i,50,0) rep(j,0,n) if (dp[i+1][j]) rep(k,0,i<t) rep(l,0,pp[i]) {
        //     int x=2*j+k-l;
        //     ll w=dp[i+1][j]*C[pp[i]-(i<t)][l]%mod*I2[pp[i]]%mod;
        //     if (x>n) (tot+=w)%=mod;
        //     else if (x>=0) (dp[i][x]+=w)%=mod;
        // }
        // rep(k,0,n) (tot+=calc(n-1,k)*dp[0][k])%=mod;
        // (ans+=mod-tot*cc[t]%mod)%=mod;
    // }
    cout<<ans<<'\n';
    return 0;
}