View Code of Problem 3695

#include<stdio.h>
int main(){
  long a[90];
  a[0]=1;a[1]=2;
  for(int i=2;i<90;i++)
    a[i]=a[i-1]+a[i-2];
  
  long t,n,sum;
  scanf("%ld",&t);
  
  while(t--){
    scanf("%d",&n);
    sum=0;
    for(int i=0;i<n;i++)
      sum+=a[i];
    printf("%ld\n",sum);
  }
}