Given a proof for a result, one could denote the proof as a node on a graph, and then draw arrows to the node from axioms and previous results that the proof uses, and then draw arrows from the node to results that the result is used to prove. The sources of such a graph would be mathematical axi...

As part of many hobbies (origami, sculpting, construction toys) I often find myself building polyhedra from regular polygons. I am intimately familiar with all of the Archimedean and Platonic solids, and can construct most of the other isohedra, deltahedra, and Johnson solids from memory. The sm...

Do You know any kind of database of presentations of groups? It may be on-line or off-line in form of tables, ideally case would be integrated in some Computer Algebra System. I am interested the most in infinite group presentations, but feel free to put here also information about tables of pr...

I am studying graph algorithms. I need database of graphs on which I can test my algorithms. Where can I find reliable database of graphs of all kinds? Thanks!

Knots such as the 3_1 knot and the 4_1 knot are often referred to as the trefoil and figure-eight knots respectively. There are more obscure names for some of the later ones in the knot tables, for example the 6_1 knot is also know as the stevedore knot. These names are not listed on the online k...

This is a soft question but it's not meant as a big-list question. I have recently been asked whether I want to provide feedback at the pre-beta stage on a forthcoming website that will provide a platform for data sharing, and rather than giving just my personal opinion I'd rather consult other m...

Is there somewhere a database of incidence matrices of generalized quadrangles that one can download?

Is there somewhere a database on Maass forms that includes eigenvalues, Taylor coefficients, etc...? I am mainly interested in classical forms on $\Gamma(1)\backslash H$.

At one point, I remember being excited by seeing the website Encyclopedia of Combinatorial Structures as an extension of Sloane's Online Integer Sequence Database site. Unfortunately, the site (ECS) has already become largely defunct. I would very much like to see a searchable database of combin...

Is anyone aware of any attempt to describe the dependencies of theorems (perhaps in mathematics generally, perhaps in some limited areas) in the form of a "family tree"? That is, each node on the tree might correspond to a theorem, and branches would indicate dependencies between theorems? I re...

Is there a repository of cospectral non-isomorphic graphs available somewhere? I am looking for list of $0/1$ adjacency matrix pairs that can be input data in tools such as MATLAB.

Given a proof for a result, one could denote the proof as a node on a graph, and then draw arrows to the node from axioms and previous results that the proof uses, and then draw arrows from the node to results that the result is used to prove. The sources of such a graph would be mathematical axi...

On MO there were several questions regarding databases of (some type of) mathematical objects. You can see the list of questions I was able to find here. What would be correct tag for such questions? I can think of three possible answers which seem to be reasonable (at least to some extent) We...

Navigating MO, it is possible to view two kinds of questions regarding errors within a book. The first kind are community-wiki questions which answers are a collaborative listing of found errors in a book (e.g.: Errata to Principles of Algebraic Geometry, Errata for Atiyah-Macdonald, Erratum for ...

Maybe it could be called book-errata? I cannot give many examples of discussions from math.SE offhand but at least one example from here Find limit of unknown function This is an example from a different forum: http://www.sosmath.com/CBB/viewtopic.php?p=181367 I guess questions (and answers) r...