Question: 
Write a function to find ln, m lobb number.


Model's Code:
def lobb_num(n, m):
    if m == 0:
        return 1
    return sum(lobb_num(n - 1, k) for k in range(m)) + n * lobb_num(n, m - 1)



Sample Correct Code:
def binomial_coeff(n, k): 
	C = [[0 for j in range(k + 1)] 
			for i in range(n + 1)] 
	for i in range(0, n + 1): 
		for j in range(0, min(i, k) + 1): 
			if (j == 0 or j == i): 
				C[i][j] = 1
			else: 
				C[i][j] = (C[i - 1][j - 1] 
							+ C[i - 1][j]) 
	return C[n][k] 
def lobb_num(n, m): 
	return (((2 * m + 1) *
		binomial_coeff(2 * n, m + n)) 
					/ (m + n + 1))


Asserts:
assert int(lobb_num(5, 3)) == 35
assert int(lobb_num(3, 2)) == 5
assert int(lobb_num(4, 2)) == 20


Tests:
Test 1 of 3: FAIL: AssertionError()

Test 912 of 974: 702/912 (76.97368421052632%): failed