My list of sizes looks remarkably similar to the numbers in the Universal Table from Marvel Super Heroes (FASERIP), but in a quirk of timing I developed the system whilst we were playing Star Frontiers and just before I'd read the FASERIP rules (after an endorsement of them by ZakS), but I should give them a shout-out as the earliest such progression I've seen in RPGs:
The real oddity in this system is that normally every other category doubles, except 2->4 and 10->20 where it doubles in a single category. Very strange. I'd have gone with 4, 6, 8, 10, 15, 20, 30, 40, 50, 75, 100, 150.
Anyone know why it's such an odd progression?