P16415_ca_Reines__1_.cc

#include <iostream> 
#include <vector>
using namespace std;

int main () {
    int n;
    cin >> n;
    vector <long> v {    1, 0, 0, 2, 10, 4, 40, 92, 352, 724, 2680, 14200, 73712, 365596, 2279184, 14772512, 95815104, 666090624, 4968057848, 39029188884, 314666222712, 2691008701644, 24233937684440, 227514171973736, 2207893435808352, 22317699616364044};
    cout << v[n-1] << endl;
}