def pascals_triangle(n): x=[[1]] for i in range(n-1): x.append([sum(i) for i in zip([0]+x[-1],x[-1]+[0])]) return x Call it: for x in pascals_triangle(10): print('{0:^39}'.format(x)) Output: [1] [1, 1] [1, 2, 1] [1, 3, 3, 1] [1, 4, 6, 4, 1] [1, 5, 10, 10, 5, 1] [1, 6, 15, 20, 15, 6, 1] [1, 7, 21, 35, 35, 21, 7, 1] [1, 8, 28, 56, 70, 56, 28, 8, 1] [1, 9, 36, 84, 126, 126, 84, 36, 9, 1]