To print pattern in java

Question

Input=5
1
2 9
3 8 10
4 7 11 14
5 6 12 13 15

Answer 1

im unaware of the one that i have posted earlier i will delete that one

Answer 2

It's a practical Excersize for logical thinking.. Just give a try and share your logic with code if it unsolved. Then some one help you complete it.
Hint : the number differences for next number and for next line are in a series. Find it.