If you sort the numbers, then represent them as the amount you need to add to the prior number[1], it produces a very small file once compressed...about 4k[2].

So, even with the code to turn it back into a list, handle the leading zeros on many numbers, etc, it would be under 10k total, much smaller than the crazy regex.

Not general purpose, and a bit silly, but you can get the list pretty damn small.

[1] Like: "1234, 1235, 1435: becomes "1234, 1, 200"

[2] The < 4k gz file that you can reproduce most of the list from: https://github.com/tyingq/barclays/blob/main/out.c.gz?raw=tr... Gunzip, then read each line, then add the prior read line to it, prepend a leading zero and print. "Prior read line" is 0 for the first line. There's a small amount of the list you would have to hardcode or handle another way...the numbers without leading zeros, total of 63 numbers.