有关pell数列的题

#include<stdio.h>

int a[31];
int calculate(int n){
    if(n == 1){
        return 1;
    }
    if(n == 2){
        return 2;
    }
    return 2 * calculate(n - 1) + calculate(n - 2);
}

int record(){
    for(int i = 1;i <= 30;i++){
        a[i] = calculate(i);
    }
}
int main(){
    int n,k;
    record();//打表
    scanf("%d",&n);
    while(n--){
        scanf("%d",&k);
        printf("%d\n",a[k]);
    }
}