September 2003 - mathfun@mailman.xmission.com

[math-fun] BSD
by Jon Perry 12 Sep '03

12 Sep '03

With the Birch-Swinnerton-Dyer conjecture, has anyone ever taken the logarithmic derivative of the Euler product in question wrt to the Euler product, and followed this line of argument through into the Taylor series? Jon Perry perry(a)globalnet.co.uk http://www.users.globalnet.co.uk/~perry/maths/ http://www.users.globalnet.co.uk/~perry/DIVMenu/ BrainBench MVP for HTML and JavaScript http://www.brainbench.com

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[math-fun] n is prime iff
by Jon Perry 11 Sep '03

11 Sep '03

[1+sum(i=1,n-1,sigma(i)*part(n-i)}]/part(n-1) = n where part(k) is the k-th partition number. (see http://www.users.globalnet.co.uk/~perry/maths/morepartitionfunction/morepart itionfunction.htm for derivation; { parts=makePartitions(40); partSigma=vector(40); partSigma[1]=1; for (i=2,40,partSigma[i]=i*parts[i]-sum(j=1,i-1,parts[j]*partSigma[i-j])); partSigma } towards the end. Jon Perry perry(a)globalnet.co.uk http://www.users.globalnet.co.uk/~perry/maths/ http://www.users.globalnet.co.uk/~perry/DIVMenu/ BrainBench MVP for HTML and JavaScript http://www.brainbench.com

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[math-fun] New books on experimental math
by David H Bailey 11 Sep '03

11 Sep '03

As some of you are aware, Jon Borwein of Canada, myself and Roland Girgensohn of Germany(for vol 2) are co-authoring a two-volume work on experimental math. This is now complete, and should be out on the street in two or three months. In the meantime, we are pleased to announce that a "Reader's Digest" version is freely available on the Web, at the URL: http://www.expmath.info/expbook-C.pdf This is about 70 pages long, and includes excerpts from three chapters of the first volume, and three from the second. It gives a good taste of what the two books are about. In general, you may also be interested in the website http://www.expmath.info, where the condensed book is located, which was set up specifically to support our book. It includes numerous links to interesting and useful math websites. Cheers, David H Bailey david(a)dhbailey.com or dhbailey(a)lbl.gov

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[math-fun] more 51 star designs
by Richard Schroeppel 11 Sep '03

11 Sep '03

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Rich rcs(a)cs.arizona.edu

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Antwort: [math-fun] World Flag
by dirk.lattermann＠bgs-ag.de 11 Sep '03

11 Sep '03

The premise of this question is void: If there were total harmony in the world, no flag would be needed, or at least, its appearance would not matter. Greetings, Dirk Lattermann "Jon Perry" <perry(a)globalnet.co.uk>@mailman.xmission.com am 11.09.2003 14:17:48 Bitte antworten an math-fun <math-fun(a)mailman.xmission.com> Gesendet von: math-fun-bounces(a)mailman.xmission.com An: "Maths is Fun" <math-fun(a)mailman.xmission.com> Kopie: Thema: [math-fun] World Flag With all this flag talk, let's imagine total harmony in the world, and a world flag is needed. What would it look like? Jon Perry perry(a)globalnet.co.uk http://www.users.globalnet.co.uk/~perry/maths/ http://www.users.globalnet.co.uk/~perry/DIVMenu/ BrainBench MVP for HTML and JavaScript http://www.brainbench.com _______________________________________________ math-fun mailing list math-fun(a)mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun

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[math-fun] World Flag
by Jon Perry 11 Sep '03

11 Sep '03

With all this flag talk, let's imagine total harmony in the world, and a world flag is needed. What would it look like? Jon Perry perry(a)globalnet.co.uk http://www.users.globalnet.co.uk/~perry/maths/ http://www.users.globalnet.co.uk/~perry/DIVMenu/ BrainBench MVP for HTML and JavaScript http://www.brainbench.com

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[math-fun] abcd
by Jon Perry 09 Sep '03

09 Sep '03

Can someone characterize the integer solutions to: ad + bc + bd = ac These correspond to pairs of complex numbers (a+bi)(c+di) such that the real part (ac-bd) is equal to the imaginary part (ad+bc). In Pari; { for (a=1,50, for (b=1,50, for (c=1,50, for (d=1,50, if (a*d+b*c+b*d==a*c,print(a","b","c","d)))))) } gives (e.g.) 10,8,9,1 10,8,18,2 10,8,27,3 10,8,36,4 10,8,45,5 Jon Perry perry(a)globalnet.co.uk http://www.users.globalnet.co.uk/~perry/maths/ http://www.users.globalnet.co.uk/~perry/DIVMenu/ BrainBench MVP for HTML and JavaScript http://www.brainbench.com

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[math-fun] David Robbins
by James Propp 09 Sep '03

09 Sep '03

Forwarded from Greg Kuperberg (greg(a)math.ucdavis.edu) >I just found out, and I'm very sorry to report, that David Robbins died >yesterday (September 4). He was 60 or 61. As the Wall Street Journal >article explained, he was diagnosed with pancreatic cancer in May. >Clara Chan and Lynn Butler arranged a very nice conference for him in >June, in which I was happy to participate. Still, this was terrible >luck for him, and unfortunate for all of us. > >-- > /\ Greg Kuperberg (UC Davis) > / \ > \ / Visit the Math ArXiv Front at http://front.math.ucdavis.edu/ > \/ * All the math that's fit to e-print * Jim Propp

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Re: [math-fun] more 51 star designs
by David Wilson 09 Sep '03

09 Sep '03

I would arrange 51 stars in a centered pentagonal arrangement. It would have a pretty 5-way symmetry, and would play on the lines of the stars. True, it's not rectangular, but then neither was the circle of 13 stars...

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[math-fun] Prime Graphs
by Jon Perry 08 Sep '03

08 Sep '03

Just for review, no comments required, (and apologies to PrimeForm for being slighly skew); http://www.users.globalnet.co.uk/~perry/maths/primegraph/primegraph.htm Jon Perry perry(a)globalnet.co.uk http://www.users.globalnet.co.uk/~perry/maths/ http://www.users.globalnet.co.uk/~perry/DIVMenu/ BrainBench MVP for HTML and JavaScript http://www.brainbench.com

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