Question: 
Write a function to find the nth hexagonal number.


Model's Code:
def hexagonal_num(n):
    return n * (2 * n - 1)



Sample Correct Code:
def hexagonal_num(n): 
	return n*(2*n - 1) 


Asserts:
assert hexagonal_num(10) == 190
assert hexagonal_num(5) == 45
assert hexagonal_num(7) == 91


Tests:
Test 1 of 3: PASS
Test 2 of 3: PASS
Test 3 of 3: PASS

Test 135 of 974: 101/135 (74.81481481481481%): success