#include <iostream> using namespace std; int friendsPairing(int n){ //Base case if(n==0 || n==1) return 1; //Recursive case else return friendsPairing(n-1)+ (friendsPairing(n-2)* (n-1)); } int main() { int t; cin>>t; while(t--) { int n; cin>>n; cout<<friendsPairing(n)<<endl; } return 0; }