As per the given pattern, it can be observed that,

(i) The third number is the multiplication of the first two numbers

(ii) The fourth number can be obtained by adding 1 to the third number

Hence, the missing numbers in the pattern will be:

4² + 5² +20² = 21²

5² +6² + 30² = 31²

6² + 7² +42² =43²