A number is happy if recursively all the sums of squares of inidividual digits equal 1 otherwise its false if numbers keep repeating.

happy_number.py

def happy_number(x: int, result=0, seen: Optional[set] = None) -> bool:
    seen = seen or set()
    num_to_sqr, new_num = ((x%10)**2 + result), x//10
    # print(f"1st num_to_sqr={num_to_sqr} new_num={new_num}")
    seen.add(num_to_sqr)
    # print(f"seen={seen}")
    if new_num:
        res = happy_number(new_num, num_to_sqr, seen)
        # print(f"res={res}")
        return res
    if num_to_sqr in seen:
        return False
    if num_to_sqr == 1:
        return True
    else:
        return happy_number(num_to_sqr, 0, seen)
    # print(f"num_to_sqr={num_to_sqr}")
    return False

print(happy_number(200))
print(happy_number(19))