SCP-033: A sum of symbols equal to a previously unknown integer
scp-wiki.wikidot.com
scp-wiki.wikidot.com
I couldn't get the link to work in your URL but I found the story here: http://strangehorizons.com/fiction/the-secret-number/
They made it into a short film: https://www.youtube.com/watch?v=VCE65wBcij8
I like how the hackernews post for "The Secret Number" has a post referencing SCP-033 and SCP-033 now has a post referencing "The Secret Number". They point at each other.