How many small squares will there be in step 4? How many small squares will there be in step 15?

Question

Do not include the units of (squares) in your answer

Answer 1

Note the number of the Step is being squared:

Step 1: 1² → 1 unit

Step 2: 2² → 4 units

Step 3: 3² → 9 units

Step 4: 4² → 16 units

..............................

Step 15: 15² → 225 units

Answer 2

1, 4, 9

1, 1+3, 4+ 5

So I would say

9+7, 16+9, 25+11