Splite num sequence

Num123.java

package com.Test;

public class Num123 {
	public static void main(String[] args) {
		int n = 5;
		
		foo(2, n, "1");
	}
	
	public static void foo(Integer i, Integer n, String s) {
		if (i == n) {
			log(s + " " + i.toString() + "\n");
			log(s + i.toString() + "\n");
			
			return ;
		}
		foo(i + 1, n, s + " " + i);
		foo(i + 1, n, s + i.toString());
	}
	
	public static void log(Object obj) {
		System.out.print(obj.toString());
	}
}