Comment by rawnlq

A more layman version:

- Each value generates a sequence of coin flips

- Count the number of consecutive heads until you hit your first tail

- Take the longest streak amongst all your values, call it n

- Report 2^n as your estimate

This works because if you only have a few people flipping, you won't get a lot of long streaks.

But if you had lets say 1024 flippers, you expect to see one person flip 10 consecutive heads.

Coins flips here are just the bits generated by hashing the value so each coin flip sequence will be the same for each value.