#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 7;
long long t, n, k, a[N], v[N << 1], kk, ans;
inline void add(long long x, long long t) {
  for (; x <= kk; x += x & -x) v[x] += t;
}
inline long long query(long long x) {
  long long ans = 0;
  for (; x > 0; x ^= x & -x) ans += v[x];
  return ans;
}
int main() {
  cin >> t;
  while (t--) {
    scanf("%lld%lld", &n, &k);
    kk = k << 1;
    for (register int i = 1; i <= n; i++) scanf("%lld", &a[i]);
    for (register int i = 2; i <= kk; i++) v[i] = 0;
    for (register int i = 1; (i << 1) <= n; i++) {
      add(2, 2);
      add(min(a[i], a[n - i + 1]) + 1, -1);
      add(a[i] + a[n - i + 1], -1);
      add(a[i] + a[n - i + 1] + 1, 1);
      int t = max(a[i], a[n - i + 1]);
      add(t + k + 1, 1);
    }
    ans = query(2);
    for (register int i = 3; i <= kk; i++) ans = min(ans, query(i));
    cout << ans << endl;
  }
  return 0;
}
