C :

#include<stdio.h>   //142431395
//#include <windows.h>
int main()
{
	int num[7]={1,2,3,4,5,9};
	int vis[7]={0};
	int a1,a2,a3,a4,a5,a6;
	int t;
	int flag=0;
	int cnt;
	cnt=0;
	//unsigned uEndTime;
	//unsigned uStartTime = GetTickCount();
	//freopen("in.txt", "r", stdin);
    //freopen("out.txt", "w", stdout);
	for(a1=0;a1<6;a1++){
		vis[a1]=1;
		for(a2=0;a2<6;a2++){
			if(vis[a2]==1)
				continue;
			vis[a2]=1;
			for(a3=0;a3<6;a3++){
				if(vis[a3]==1)
					continue;
				vis[a3]=1;
				for(a4=0;a4<6;a4++){
					if(vis[a4]==1)
						continue;
					vis[a4]=1;
					for(a5=0;a5<6;a5++){
						if(vis[a5]==1)
							continue;
						vis[a5]=1;
						for(a6=0;a6<6;a6++){
							if(vis[a6]==1)
								continue;
							vis[a6]=1;
							t=100000000*num[a1]+1000*num[a1]+10000000*num[a2]+100000*num[a2]+1000000*num[a3]+10000*num[a4]+100*num[a4]+10*num[a5]+num[a6];
							cnt++;
					//		printf("%d %d\n",t,cnt);
							if(cnt==50) {
								printf("%d%d%d%d%d%d%d%d%d\n",num[a1],num[a2],num[a3],num[a2],num[a4],num[a1],num[a4],num[a5],num[a6]);
								flag=1;
							}
							vis[a6]=0;
							if(flag==1) break;
						}
						vis[a5]=0;
						if(flag==1) break;
					}
					vis[a4]=0;
					if(flag==1) break;
				}
				vis[a3]=0;
				if(flag==1) break;
			}
			vis[a2]=0;
			if(flag==1) break;
		}
		vis[a1]=0;
		if(flag==1) break;
	}
	//uEndTime = GetTickCount();
//	printf("%ums elapsed.\n",uEndTime-uStartTime);
	//fclose(stdin);
  //  fclose(stdout);
	return 0;
}

C++ :

#include<iostream>  //142431395
using  namespace std;
int main()
{
	cout<<"142431395"<<endl;
}