#pragma ide diagnostic ignored "misc-no-recursion"

#include "bits/stdc++.h"

using namespace std;
typedef long long ll;
typedef double db;

#define TESTCASE 1

static constexpr int INF = 1e9;

#define int long long
const long long mod = 998'244'353ll;
const int MAXN = 5005;
long long invfact[MAXN];

static void solve([[maybe_unused]] int tc) {

    int n;
    cin>>n;
    vector a(n,0),succ(n,0);
    for(auto &i : a)cin>>i;

    if(n==2){
        if(a[0]==a[1])cout<<"0\n";
        else cout<<"1\n";
        return;
    }
    sort(a.begin(),a.end());
    int last = n;
    for(int i=n-1;i>=0;i--){
        succ[i]=last;
        if(i>0 && a[i]!=a[i-1])last=i;
    }

    vector dp(n,vector(n,-1ll));

    auto f = [&](auto f,int pos,int num)->long long{
        if(pos==n)return 0;
        if(dp[pos][num]!=-1)return dp[pos][num];

        long long ans=f(f,succ[pos],num);

        if(num==0)ans+=f(f,succ[pos],num+1)*(succ[pos]-pos)%mod*pos%mod*(pos-1)%mod;
        else if(num==n/2-1){
            //assert(pos==n-1);
            ans++;
        }
        else if(pos-2*num-1>0)ans+=f(f,succ[pos],num+1)*(succ[pos]-pos)%mod*(pos-2*num-1)%mod;

        ans%=mod;
        assert(ans>=0 && ans<mod);
        //cout<<pos<<" "<<num<<" "<<ans<<"\n";
        return dp[pos][num]=ans;
    };



    long long ans = f(f,0,0);
    for(int i=0;i<n;){
        ans*=invfact[succ[i]-i];
        ans%=mod;
        i=succ[i];
    }

    cout<<ans<<"\n";
}

long long fastp(long long base,long long exp) {
    if(exp==0)return 1;

    long long tmp = fastp(base,exp/2);
    tmp = tmp*tmp%mod;

    if(exp%2==1)tmp=tmp*base%mod;
    return tmp;
}

signed main() {
    ios::sync_with_stdio(false);

    if (const char *f = getenv("REDIRECT_STDOUT"); f) {
        freopen(f, "w", stdout);
    }

    invfact[0]=1;
    for(int i=1;i<MAXN;i++){
        invfact[i]=invfact[i-1]*fastp(i,mod-2ll)%mod;
    }
    //cout<<fastp(2,mod-2ll)*2%mod<<"\n";
    //return 0;

    int T = 1;
#if TESTCASE
    cin >> T;
#endif

    for (int t = 1; t <= T; t++) {
        solve(t);
    }

    return 0;
}