#include <iostream> using namespace std; // 计算PELL数列的第k项 long long pell(int k) { if (k == 0) return 0; if (k == 1) return 1; long long p = 0, c = 1; long long n; for (int i = 2; i <= k; ++i) { n = 2 * c + p; p = c; c = n; } return c; } int main() { int n; cin >> n; for(int i = 0; i < n; i++){ int k; cin >> k; cout << pell(k) << endl; } return 0; }