#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define mod 998244353LL

ll f[1010][1010],c[1010][1010],fac[1010];
int num[1010],cnt[1010],sum[1010],t,n,tt;

inline int rd()
{
    int x=0;char ch=getchar();
    for (;ch<'0'||ch>'9';ch=getchar());
    for (;ch>='0'&&ch<='9';ch=getchar()) x=x*10+ch-'0';
    return x;
}

inline ll pls(const ll &x,const ll &y) { return (x+y<mod)?x+y:x+y-mod; }
inline ll mns(const ll &x,const ll &y) { return (x-y<0)?x-y+mod:x-y; }
inline ll ksm(ll x,ll y) { ll res=1;for (;y;y>>=1,x=x*x%mod) if (y&1) res=res*x%mod;return res; }

inline void pre_gao()
{
    for (int i=0;i<=1000;i++)
    {
        c[i][0]=1;
        for (int j=1;j<=i;j++) c[i][j]=pls(c[i-1][j-1],c[i-1][j]);
    }
    fac[0]=1;
    for (int i=1;i<=1000;i++) fac[i]=fac[i-1]*i%mod;
}

inline void gao()
{
    n=rd();
    for (int i=1;i<=n;i++) num[i]=rd();
    sort(num+1,num+n+1);tt=0;
    for (int i=1;i<=n;)
    {
        int j=i;
        for (;j<=n&&num[j]==num[i];j++);
        cnt[++tt]=j-i;i=j;
    }
    for (int i=1;i<=tt;i++) sum[i]=sum[i-1]+cnt[i];
    memset(f,0,sizeof(f));
    f[0][0]=1;
    for (int i=1;i<=tt;i++) for (int j=0;j<=sum[i-1];j++) if (f[i-1][j])
    {
        for (int k=0;k<=min(cnt[i],j);k++)
        {
            f[i][j-k+(cnt[i]-k)]=(f[i][j-k+(cnt[i]-k)]+f[i-1][j]*c[j][k])%mod;
        }
    }
    ll ans=0;
    for (int i=0;i<=sum[tt];i++) ans=pls(ans,f[tt][i]);
    for (int i=1;i<=tt;i++) ans=ans*fac[cnt[i]]%mod;
    printf("%I64d\n",ans);
}

int main()
{
    t=rd();pre_gao();
    while (t--) gao();
    return 0;
}