It is true ->
-> Sum_of_array = (sum_of_array (1,26) - num_1 - num_2) == num_1 * num_2,
but num_1 or num_2 > n (= 26) - so 175 > 26 - it is not correct.
The condition of the task - num_1 or num_2 <= n (26)

Thanks! Good exercise! But I think is 6 or 7 kyu, but not 5 kyu. Because for O(n) you need know one rule from math and pair of condition for <O(n)