【題目敘述】https://zerojudge.tw/ShowProblem?problemid=d054
#include <iostream>
using namespace std;
long long t, n, dp[45][4];
int main() {
cin >> t;
dp[1][0] = 1;
dp[1][3] = dp[1][0]+dp[1][1]+dp[1][2];
for (int i = 2; i <= 40; i++){
dp[i][0] = dp[i-1][3];
dp[i][1] = dp[i-1][0]*2;
dp[i][2] = dp[i-1][0]*2+dp[i-1][1];
dp[i][3] = dp[i][0]+dp[i][1]+dp[i][2];
}
while (t--){
cin >> n;
cout << dp[n][3] << "\n";
}
}