Working Rule to Get Expansion of (a + b) ⁴ Using Pascal Triangle. But this approach will have O(n3) time complexity. The sum of the numbers on each row are powers of 2. The triangle now bears his name mainly because he was the first to systematically investigate its properties. ... On the one hand, each switch can be on or off, so there are $2^n$ configurations. 64 = 63 + 1. The row-sum of the pascal triangle is 1<