> And it happens to be the case that 7 × 9 = 63, which is almost 64, a power of 2 While the article goes down a different rabbit hole, this also happens to be

> And it happens to be the case that 7 × 9 = 63, which is almost 64, a power of 2 While the article goes down a different rabbit hole, this also happens to be a neat example of (n-1)(n+1) = n² - 1, where n = 8. Which is one of those things I haven't managed to find an actual use for but feels like it should have since you can use it with 0xFF (15 × 17), 0xFFFF (255 × 257), and so on.