float Sn(int n)//????????
{
	float s[n+1];//?????????
	s[0]=1;//???
	s[1]=2;  //???
	for(int k=0;k<n;k++)
		s[k+2]=s[k]+s[k+1];//????????
	float p=0;
	for (int k=0;k<n;k++)
		p=p+s[k+1]/s[k];//????
	return p;//?????
}
int main()//??? 
{ 
	int m;
	cin>>m;//????
	int a[m];//??????
	for (int k=0;k<m;k++)
		cin>>a[k];//??????????????????n
	for (int k=0;k<m;k++)
	{
		printf("%.3f",Sn(a[k]));//???????
		printf("\n");//??
	}
	return 0;
}
















