if you remember this whole triangle idea:
1
0 1 1
1 0 0 1
0 1 1 0 1
…
I realized that the next row is always like, (a bunch of ones) - (the last row). so to get the next row from [0 1 1 0 1] you can subtract it from [1 1 1 1 1 1], and get [1 0 0 1 0 1].