C :

#include<stdio.h>
int main()
{
	int n,i,j=1,k=1,x[200000]={0,1},m;
	for(i=2;i<=200000;i++)
	{
		m=2*x[j]+1;
		n=4*x[k]+5;
		if(m>n){x[i]=n;k++;}else{x[i]=m;j++;}
	}
	while(scanf("%d",&n)==1)
		printf("%d\n",x[n]);
	return 0;
}

C++ :

#include <bits/stdc++.h>
using namespace std;

#define maxn 200005
int d[maxn];

int main()
{
	int index1=0,index2=0;
	int num=1;
	d[0]=1;
	while(num<maxn){
		int b1=d[index1]*2+1;
		int b2=d[index2]*4+5;
		if (b1<=b2){
			d[num++]=b1;
			index1++;
		} else d[num++]=b2,index2++;
	}
	
	int n;
	while(~scanf("%d",&n)){
		printf("%d\n",d[n-1]);
	}
	return 0;
}