TITLE: Is there a website like OEIS for real constants?
QUESTION [25 upvotes]: I'm hoping an online service exists where I can type in say 3.14159 and it then shows a bunch of 'interesting' (however one would define that) numbers.
Naturally in that instance it would bring up $\pi$ first as the most likely candidate, then $355/113$ then increasingly more bizarre numbers. Ideally with a weighting towards use of irrational/transcendental numbers and simplicity of expression.
I have a very messy expression that is currently graphed and I want to find out if the maximum of the graph is a known number.
Thanks in advance!

REPLY [9 votes]: Wolfram|Alpha (https://www.wolframalpha.com) can return an assortment of information about a decimal number including a list of possible closed forms, e.g.
https://www.wolframalpha.com/input/?i=1.303577269034
https://isc.carma.newcastle.edu.au/ did not do anything useful with this particular number.