I’m guessing they chose $512,000 because “512” is a power of 2 and systems programmers love that sort of shit, but 2^19 is 524,288. I mean $12,288 is not insignificant but it would have been cooler.
I'm not sure how many people would recognize 524,288 as a power of 2, but probably many fewer than the number of people who would recognize 512 as a power of 2
Maybe they count like storage manufacturers. 512 kilobytes instead of kibibytes :)
It's $256k each from two companies, in monthly instalments, which ends up not being particularly close to a power of 2 each month.
Maybe their donation was in $1000 bills
Someone already covered the difference: https://news.ycombinator.com/item?id=45703926#45703995
Mad props to them for picking up my joke and turning it into a recurring donation.