I’ve received the following note from Barry Cipra, bit-player’s Bureau Chief in Northfield, Minnesota, (where all hail broke loose yesterday):

Your latest postings [here and here] have motivated me to idle away some time with a variant of the problem(s) you discussed. To wit, I got to wondering what happens if you restrict yourself to taking […]

Kevin O’Bryant, whose work on sets that have more sums than differences was mentioned in this recent post, writes as follows:

Here’s a related problem that Mel Nathanson and myself (with Ruzsa and a few students) have also been thinking about. For a finite set A of integers, let S = {a + b : a,b […]

Take a set of integers, say {0, 2, 5, 8, 11}, and write down all the numbers that can be represented as sums of two elements drawn from this set. For our example the answer is {0, 2, 4, 5, 7, 8, 10, 11, 13, 16, 19, 22}. Now construct the corresponding set of pairwise […]

The new issue (September-October) of American Scientist is available on the Web, and subscribers to the ink-and-paper edition should receive copies soon. My “Computing Science” column is more topical than I would like, given today’s headlines. I examine some ideas from graph theory and social-networking studies that intelligence agencies may (or may not—who knows?) be […]

I can cook anything, as long as the recipe starts with “Take it out of the freezer” and ends with “Put it in the microwave.”
Go ahead and scoff, but I’m proud of my culinary accomplishments. Furthermore, I submit that the art of microwaving frozen foods is not without intellectual challenge. Inferior technique could leave […]

The banner image at the top of this page might be taken for an algorithmic attempt to imitate a fern, although in my opinion the pattern bears a closer resemblance to the two-dimensional corals known as sea fans, or gorgonians. The image below also reminds me of some sort of sessile sea creature—if not a […]

A few years ago Michael Berry revealed that his first choice in reading matter, if he were stranded on a desert island, would be Abramowitz and Stegun, also known as Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables, published by the National Bureau of Standards in 1964. For those of you seeking lighter […]