Is there a website like OEIS for real constants?

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!

Solution 1:

Inverse symbolic calculator plus:

https://isc.carma.newcastle.edu.au/

Solution 2:

There is also a tool RIES - Find Algebraic Equations, Given Their Solution with the source code available.

Solution 3:

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.

Solution 4:

This is not really what you want. But a method that you can try is the lowest denominator method.

How this works is you have a value $\alpha$ and a margin $\epsilon$.

You then return the value of the form $\frac{mc}{n}$ inside $(\alpha-\epsilon,\alpha+\epsilon)$ that minimizes $n$. Here you take $c$ inside a set of constants, a preliminary set could be $\{1,\pi,e,\pi^{-1},e^{-1}\}$