Category Archives: people

17×17 4-coloring with no monochromatic rectangles

Posted on February 9, 2012 by

Quick, what’s special about the following picture? As just announced by Bill Gasarch, this is a grid which has been four-colored (that is, each point in the grid has been assigned one of four colors) in such a way that … Continue reading →

Posted in open problems, pattern, people, pictures | Tagged , , , , , | 5 Comments

Herbert Wilf: 13 June 1931 – 7 January 2012

Posted on January 9, 2012 by

I was sad to learn that Herbert Wilf died yesterday. Long-time readers of this blog may remember him as one of the discoverers of the Calkin-Wilf tree, which I wrote about in a ten-part series of posts (1, 2, 3, … Continue reading →

Posted in people | Tagged | 1 Comment

Book review: Magical Mathematics

Posted on October 20, 2011 by

Occasionally someone from Princeton University Press sends me a list of upcoming titles and asks if there are any I’d like to review. I jumped when I saw this one: a book about magic tricks and math! By Persi Diaconis … Continue reading →

Posted in books, people, review | Tagged , , , , | 3 Comments

Relatively Prime: Stories from the Mathematical Domain

Posted on July 28, 2011 by

Samuel Hansen needs your help! He’s currently raising money to create a series of podcasts explaining math to a wide audience. From the linked video, it looks like they will be a lot of fun, and I think it would … Continue reading →

Posted in links, people | Tagged , ,

The wonderful world of Mike Reilly

Posted on June 14, 2011 by

The other day I received an email from Mike Reilly, who introduced himself as a professional game and puzzle inventor, and suggested that I might be interested in taking a look at a few of his web sites. I wasn’t … Continue reading →

Posted in games, links, people, puzzles | Tagged , , , , , | 2 Comments

Vi Hart's math doodles

Posted on December 14, 2010 by

Vi Hart’s math doodle videos have been making the rounds of the math blogosphere (I heard of them from Denise at Let’s Play Math!). There are four videos so far and they are well worth watching — inspirational, creative, full … Continue reading →

Posted in games, humor, links, people, video | Tagged , , , | 2 Comments

The mathematics of human knots

Posted on November 19, 2010 by

Have you ever played “human knot”? It seems to be a common icebreaker/team-building sort of exercise (just do a Google search for “human knot” and you’ll find quite a few pages discussing it). Everyone stands in a circle, then reaches … Continue reading →

Posted in games, people, probability | Tagged , , , , , | 9 Comments

P ≠ NP?

Posted on August 10, 2010 by

A few days ago, Vinay Deolalikar, a Principal Research Scientist at HP Labs, began circulating a draft of a paper entitled “P ≠ NP”. The mathematics and computer science communities immediately erupted in a frenzy of excitement and activity. The … Continue reading →

Posted in computation, links, open problems, people, proof | Tagged , , , | 7 Comments

Carnival of Mathematics this Friday!

Posted on December 1, 2009 by

The next Carnival of Mathematics goes up this Friday at idiot’s blog—get your submissions in!

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Hyperbinary conjecture seeking proof for a good time, long walks on the beach

Posted on October 12, 2009 by

Here’s the latest progress on the hyperbinary sequence. We’re trying to figure out the inverse relation of the function : given a particular number , where does it occur in the hyperbinary sequence? That is, what are the values of … Continue reading →

Posted in challenges, pattern, people, proof, sequences | Tagged , , , | 4 Comments