View Code of Problem 73

#include<stdio.h>
int main()
{
	int i,n;
	scanf("%d",&n);
	int sum[1000];
	sum[n] = 1;
	for(i=n-1;i>=1;i--)
	{
		sum[i] = (sum[i+1]+1)*2;
	}
	printf("%d",sum[1]);
	return 0;
}