#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

using Int = long long;

template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> ostream &operator<<(ostream &os, const vector<T> &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; }
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }
#define COLOR(s) ("\x1b[" s "m")

////////////////////////////////////////////////////////////////////////////////
template <unsigned M_> struct ModInt {
  static constexpr unsigned M = M_;
  unsigned x;
  constexpr ModInt() : x(0U) {}
  constexpr ModInt(unsigned x_) : x(x_ % M) {}
  constexpr ModInt(unsigned long long x_) : x(x_ % M) {}
  constexpr ModInt(int x_) : x(((x_ %= static_cast<int>(M)) < 0) ? (x_ + static_cast<int>(M)) : x_) {}
  constexpr ModInt(long long x_) : x(((x_ %= static_cast<long long>(M)) < 0) ? (x_ + static_cast<long long>(M)) : x_) {}
  ModInt &operator+=(const ModInt &a) { x = ((x += a.x) >= M) ? (x - M) : x; return *this; }
  ModInt &operator-=(const ModInt &a) { x = ((x -= a.x) >= M) ? (x + M) : x; return *this; }
  ModInt &operator*=(const ModInt &a) { x = (static_cast<unsigned long long>(x) * a.x) % M; return *this; }
  ModInt &operator/=(const ModInt &a) { return (*this *= a.inv()); }
  ModInt pow(long long e) const {
    if (e < 0) return inv().pow(-e);
    ModInt a = *this, b = 1U; for (; e; e >>= 1) { if (e & 1) b *= a; a *= a; } return b;
  }
  ModInt inv() const {
    unsigned a = M, b = x; int y = 0, z = 1;
    for (; b; ) { const unsigned q = a / b; const unsigned c = a - q * b; a = b; b = c; const int w = y - static_cast<int>(q) * z; y = z; z = w; }
    assert(a == 1U); return ModInt(y);
  }
  ModInt operator+() const { return *this; }
  ModInt operator-() const { ModInt a; a.x = x ? (M - x) : 0U; return a; }
  ModInt operator+(const ModInt &a) const { return (ModInt(*this) += a); }
  ModInt operator-(const ModInt &a) const { return (ModInt(*this) -= a); }
  ModInt operator*(const ModInt &a) const { return (ModInt(*this) *= a); }
  ModInt operator/(const ModInt &a) const { return (ModInt(*this) /= a); }
  template <class T> friend ModInt operator+(T a, const ModInt &b) { return (ModInt(a) += b); }
  template <class T> friend ModInt operator-(T a, const ModInt &b) { return (ModInt(a) -= b); }
  template <class T> friend ModInt operator*(T a, const ModInt &b) { return (ModInt(a) *= b); }
  template <class T> friend ModInt operator/(T a, const ModInt &b) { return (ModInt(a) /= b); }
  explicit operator bool() const { return x; }
  bool operator==(const ModInt &a) const { return (x == a.x); }
  bool operator!=(const ModInt &a) const { return (x != a.x); }
  friend std::ostream &operator<<(std::ostream &os, const ModInt &a) { return os << a.x; }
};
////////////////////////////////////////////////////////////////////////////////

constexpr unsigned MO = 998244353;
using Mint = ModInt<MO>;

constexpr int LIM_INV = 4010;
Mint inv[LIM_INV], fac[LIM_INV], invFac[LIM_INV];

void prepare() {
  inv[1] = 1;
  for (int i = 2; i < LIM_INV; ++i) {
    inv[i] = -((Mint::M / i) * inv[Mint::M % i]);
  }
  fac[0] = invFac[0] = 1;
  for (int i = 1; i < LIM_INV; ++i) {
    fac[i] = fac[i - 1] * i;
    invFac[i] = invFac[i - 1] * inv[i];
  }
}
Mint binom(Int n, Int k) {
  if (n < 0) {
    if (k >= 0) {
      return ((k & 1) ? -1 : +1) * binom(-n + k - 1, k);
    } else if (n - k >= 0) {
      return (((n - k) & 1) ? -1 : +1) * binom(-k - 1, n - k);
    } else {
      return 0;
    }
  } else {
    if (0 <= k && k <= n) {
      assert(n < LIM_INV);
      return fac[n] * invFac[k] * invFac[n - k];
    } else {
      return 0;
    }
  }
}

Mint match[LIM_INV];


// \sum[x \in (Z/2Z)^n] (-1)^(\sum[u<=v] adj[u][v])
namespace solver {
constexpr int MAX_N = 2010;
int n;
bitset<MAX_N> adj[MAX_N];
void init(int n_) {
  assert(n_ >= 0);
  n = n_;
  for (int u = 0; u < n; ++u) adj[u].reset();
}
void ae(int u, int v) {
  assert(0 <= u); assert(u < n);
  assert(0 <= v); assert(v < n);
  adj[u].flip(v);
  if (u != v) adj[v].flip(u);
}
Mint run() {
  vector<int> del(n, 0);
  Mint ans = 1;
  for (int u = 0; u < n; ++u) if (!del[u]) {
    del[u] = 1;
    bool isol = true;
    for (int v = u + 1; v < n; ++v) if (!del[v] && adj[u][v]) {
      // \sum[x[u],x[v]] (-1)^(x[u][v] + adj[u][u] x[u] + adj[v][v] x[v] + x[u] \sum[u-w] x[w] + x[v] \sum[u-w] x[w])
      // = 2 (-1)^((adj[u][u] + \sum[u-w] x[w]) (adj[v][v] + \sum[v-w] x[w]))
      del[v] = 1;
      ans *= 2;
      if (adj[u][u] && adj[v][v]) ans = -ans;
      if (adj[u][u]) for (int w = u + 1; w < n; ++w) if (!del[w] && adj[v][w]) adj[w].flip(w);
      if (adj[v][v]) for (int w = u + 1; w < n; ++w) if (!del[w] && adj[u][w]) adj[w].flip(w);
      for (int w = u + 1; w < n; ++w) if (!del[w]) {
        if (adj[u][w] && adj[v][w]) adj[w].flip(w);
        if (adj[u][w]) adj[w] ^= adj[v];
        if (adj[v][w]) adj[w] ^= adj[u];
      }
      isol = false;
      break;
    }
    if (isol) {
      // \sum[x[u]] (-1)^(adj[u][u] x[u])
      if (adj[u][u]) {
        ans = 0;
        break;
      } else {
        ans *= 2;
      }
    }
  }
  return ans;
}
void stress() {
  for (n = 1; n <= 6; ++n) {
    for (int p = 0; p < 1 << (n*(n+1)/2); ++p) {
      init(n);
      {
        int pp = p;
        for (int u = 0; u < n; ++u) for (int v = u; v < n; ++v) {
          if (pp & 1) ae(u, v);
          pp >>= 1;
        }
      }
      Mint brt = 0;
      for (int q = 0; q < 1 << n; ++q) {
        int cnt = 0;
        for (int u = 0; u < n; ++u) if (q >> u & 1) {
          for (int v = u; v < n; ++v) if (q >> v & 1) if (adj[u][v]) {
            ++cnt;
          }
        }
        brt += ((cnt&1)?-1:+1);
      }
      const Mint res = run();
      if (brt != res) {
        int pp = p;
        for (int u = 0; u < n; ++u) for (int v = u; v < n; ++v) {
          if (pp & 1) cerr << u << " " << v << endl;
          pp >>= 1;
        }
        cerr << "brt = " << brt << ", res = " << res << endl;
      }
      assert(brt == res);
    }
    cerr << "[solver::stress] DONE n = " << n << endl;
  }
}
}  // solver



int N;
vector<int> A;

int main() {
  prepare();
  match[0] = 1;
  for (int i = 1; i < LIM_INV; ++i) {
    match[i] = match[i - 1] * (2 * i - 1);
  }
  
  // solver::stress();
  
  for (int numCases; ~scanf("%d", &numCases); ) { for (int caseId = 1; caseId <= numCases; ++caseId) {
    scanf("%d", &N);
    A.resize(N);
    for (int i = 0; i < N; ++i) {
      scanf("%d", &A[i]);
      --A[i];
    }
    
    vector<vector<int>> iss(N);
    for (int i = 0; i < N; ++i) {
      iss[A[i]].push_back(i);
    }
    
    Mint all = 1;
    for (int a = 0; a < N; ++a) {
      const int sz = iss[a].size();
      Mint sum = 0;
      for (int j = 0; 2 * j <= sz; ++j) {
        sum += binom(sz, 2 * j) * match[j];
      }
      all *= sum;
    }
    
    // \sum[select every a even times] (-1)^inversion
    int id = 0;
    vector<int> ids(N, -1);
    vector<vector<int>> uss(N);
    for (int a = 0; a < N; ++a) {
      // iss[a][0]: determined by iss[a][1, $)
      for (int k = 1; k < (int)iss[a].size(); ++k) {
        uss[a].push_back(ids[iss[a][k]] = id++);
      }
    }
    solver::init(id);
    for (int i = 0; i < N; ++i) for (int j = i + 1; j < N; ++j) if (A[i] > A[j]) {
      if (~ids[i]) {
        if (~ids[j]) {
          solver::ae(ids[i], ids[j]);
        } else {
          for (const int v : uss[A[j]]) {
            solver::ae(ids[i], v);
          }
        }
      } else {
        if (~ids[j]) {
          for (const int u : uss[A[i]]) {
            solver::ae(u, ids[j]);
          }
        } else {
          for (const int u : uss[A[i]]) for (const int v : uss[A[j]]) {
            solver::ae(u, v);
          }
        }
      }
    }
// cerr<<"solver::n = "<<solver::n<<endl;
// for(int u=0;u<solver::n;++u){for(int v=0;v<solver::n;++v)cerr<<solver::adj[u][v];cerr<<endl;}
    const Mint res = solver::run();
// cerr<<"all = "<<all<<", res = "<<res<<endl;
    
    const Mint ans = (all + res) / 2;
    printf("%u\n", ans.x);
  }
#ifndef LOCAL
  break;
#endif
  }
  return 0;
}