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Questions tagged [combinatorics]

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2
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3answers
112 views

Why are permutations ($_nP_r$) called differently in non-English languages (“variations” in German)?

First of all, you should be at least a little familiar with combinatorics to understand that question. Some often used calculator keys in stochastic are the nCr and nPr ones. Edit: I've first asked ...
4
votes
1answer
81 views

What is the origin of q-calculus notation?

It is kind of cute that q-analogues are used in physics (see this link for example), but it is also kind of confusing because the 'q' does not stand for 'quantum'. It predates that use! So, where ...
2
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0answers
74 views

Was Riddell's formula really so late?

Riddell's formula for unlabeled graphs is a generating function transformation $$1 + B(x) = \exp \sum_{k=1}^\infty \frac{A(x^k)}{k}$$ which gives the number of graphs whose connected components have a ...
6
votes
0answers
93 views

F. Schoblik's announced ''ausführliche Darstellung": a lost wrong proof of the Four Color Theorem?

In (the AMS Chelsea Publishing version of) what is perhaps the first genuine textbook on graph theory ever, Dénes Kőnig on p. 28 gives the illustration and the footnote which when translated says ...
0
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0answers
442 views

Who first proved Rota' conjecture

In Wikipedia in article about Rota's conjecture it is written: “ A proof of the conjecture has been announced by Geelen, Gerards, and Whittle” . In Quanta magazine in article about mathematician June ...
1
vote
1answer
310 views

Newton , Binomial Series and Power Series , and James Gregory

After 2 month long search on the net, I was lucky enough to find a pdf on how Newton found the series for sine. It was a beautiful derivation mostly geometrical. But he used the Binomial Series. Now ...
1
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0answers
39 views

Origin of diagrammatics illustrating the relation between cumulants and moments?

The exponential-log transformation of exponential generating functions (see OEIS A036040 and A127671) relate the classical cumulants to their associated moments. Who were some of the first to ...