View Code of Problem 73

#include<stdio.h>
int main()
{
	int n,i,j,m;
	int a[21];
	double sum=0.0;
	scanf("%d",&m);
	a[1]=1;
	for(i=2;i<=m;i++)
	{	a[i]=(a[i-1]+1)*2;
}

	printf("%d",a[m]);
}