Ask HN: What's the site that tells you interesting things about a number?

Online Encyclopedia of Integer Sequences:

Yes! that's the one. Thank you.

(Sorry forgot to upvote you)

Sorry, title won't let me make more sense. There's a site that you can supply a number and it provides mathematical interesting facts about that number. Also I don't mean "numerology".

Google is broken.

wikipedia? ex: https://en.m.wikipedia.org/wiki/9

No that's not the one. What I'm after has been quoted many times on HN.

https://www.wolframalpha.com/input?i=42 lists factoids for each number, but teh_klev was thinking of oeis