6- 10:6? = 36 ,7? = 49 ,8? = 64 ,9? = 8 1 , 10? = 100

1 1- 15: 1 1? = 12 1, 12? = 144 , 13? = 169 , 14? = 196 , 15? = 225

16-20: 16? = 256, 17? = 289 , 18? = 324, 19? = 36 1 ,20? = 400

2 1-25:2 1? = 44 1 ,22? = 484, 23? = 529 ,24? = 576, 25? = 625?

25-30:26? = 676, 27? = 729 ,28? = 784 ,29? = 84 1, 30? = 900

Extended data:

Related properties of square numbers:

1, a square number is the sum of two adjacent triangles. The sum of two adjacent squares is a central square number. All odd squares are also central octagons.

2. The sum of squares theorem shows that all positive integers can be expressed as the sum of four squares at most. In particular, the sum of three squares cannot represent the number of 4k(8m+7) shape. If a positive integer can represent the odd power of a prime number without the shape of 4k+3, it can be represented as the sum of two squares.

3. The square number must not be a perfect number.

4. If the square of odd number is divided by 4+ 1, the square of even number can be divisible by 4.

5、a？ -B? =(a+b)(a-b).

6. The square number is the sum of two adjacent triangles. The sum of two adjacent squares is a central square number. All odd squares are also central octagons.

7. The sum of squares theorem shows that all positive integers can be expressed as the sum of four squares at most. In particular, the sum of three squares cannot represent a number in the form of 4(8m+ 7). If a positive integer can represent the odd power of a factor in the form of 4k+3, and does not need a prime number, it can be represented as the sum of two squares.