Here all the number comes from squaring two numbers so just try those number whose square root is an integer number.

The input limit of this program is very little so use pre-calculation.

The output for the following input

2

4

6

8

is the following

01

81

0000

0001

2025

3025

9801

000000

000001

088209

494209

998001

00000000

00000001

04941729

07441984

24502500

25502500

52881984

60481729

99980001