CUCaTS
Puzzlehunt 2014
h(x) = fad52d091e37f2c7f5de8610327c1fd16a50545c663562a37ced0d3e26358516
author: unknown
h(x) looks like a cryptographic hash, and refreshing the page shows it changes every 5s. We find that the SHA256 hash of the unix time (floored by 5 seconds) gives us the same hash. Thus the answer is the current unix time (and values within ± a minute are accepted).