Hi,
As far as I have studied bitcoin, it's highly impossible for this addresses to came from one deterministic wallet. Please, correct me if I am wrong. Creating deterministic wallet You have no influence on final shape of priv keys so Yo can not made them,1bit, 2bit, 3bit etc.
BR
Damian
You can have a deterministic wallet and get the first 160 address. Get those private keys, mask them for you need (flip ones and zeros as you wish), and create addresses for these modified private keys.
I think these keys are from a deterministic wallet but not just 256 keys, he created like 20000 keys or more, puzzle 65 private key might be the 10000th key masked down, 66 private key the 1500th key masked down and 67 the 7600th key masked down. Just in any case some people might use the keys to derive the seed, they will always fail cause the keys are not in order the way it was generated. He said he spent two years creating this challenge, if he just generated 256 keys and masked them down, it would not take 48 hours.