#include <bits/stdc++.h>
#define last last2
#define MOD 1000000007

using namespace std;

typedef long long ll;

inline void update(ll &x,ll y) {
  x=(x+y)%MOD;
}

ll pow_mod(ll x,int k) {
  ll ans=1;
  while (k) {
      if (k&1) ans=ans*x%MOD;
      x=x*x%MOD;
      k>>=1;
  }
  return ans;
}

ll facd[200005],facv[200005];

void pre(int n) {
  facd[0]=1;
  for(int i=1;i<=n;i++) facd[i]=facd[i-1]*i%MOD;
  facv[n]=pow_mod(facd[n],MOD-2);
  for(int i=n-1;i>=0;i--) facv[i]=facv[i+1]*(i+1)%MOD;
}

inline ll C(int n,int m) {
  return (n<m)?0:facd[n]*facv[m]%MOD*facv[n-m]%MOD;
}

int a[200005],b[200005];
ll f[200005][3];

int calc(int l,int r) {
  if (l==r) return C(b[l],b[l]>>1);
  for(int i=l-1;i<=r;i++) memset(f[i],0,sizeof(f[i]));
  f[l-1][1]=1;
  for(int i=l;i<=r;i++)
    for(int j=0;j<3;j++)
      if (f[i-1][j]) {
          for(int k=((b[i]+1)>>1)-1;k<=(b[i]>>1)+1;k++) {
              int s=2*k-b[i];
              if (j+s>=0&&j+s<=2) update(f[i][j+s],f[i-1][j]*C(b[i],k));
          }
      }
  return f[r][1];
}

int solve(int n) {
  int s=0,cnt=0;
  for(int i=1;i<=n;i++) {
      s++;
      if (i==n||a[i]!=a[i+1]) {
          b[++cnt]=s;
          s=0;
      }
  }
  ll ans=1;
  bool v=0;
  int last=1;
  for(int i=1;i<=cnt;i++) {
      v^=(b[i]&1);
      if (!v) {
          ans=ans*calc(last,i)%MOD;
          last=i+1;
      }
  }
  return ans;
}

int main() {
  pre(200000);
  int cases;
  scanf("%d",&cases);
  for(;cases;cases--) {
      int n;
      scanf("%d",&n);
      for(int i=1;i<=2*n;i++) scanf("%d",&a[i]);
      printf("%d\n",solve(2*n));
  }
  return 0;
}