Archive for May 17th, 2008

Carnival of Mathematics #33: Walking Randomly Saves The Day!

May 17, 2008

Clown in the Carnival The 33rd Carnival of Mathematics is up at Walking Randomly! (who also hosted the 25th Carnival). This carnival was homeless until a couple days ago when Walking Randomly stepped up to the plate. For only having a few days to put it together, it contains an impressive number of posts. Many, but not all, have a technology bent.

The Carnival post also explains the following cool fact about the number 33: Most numbers below 1000 that are not of the form 9n±4 can be written as a sum of three signed cubes (meaning the cubes are positive or negative integers). As an aside, the way is not necessarily unique. For example, from this source:
12=73+103+(-11)3 and
12=97307053+(-9019406)3+(-5725013)3.

Up until 1999, the number 30 was the smallest positive integer that wasn’t of the form 9n±4 where there was no known way to write it as a sum of three signed cubes. But less than ten years ago a way was found (see this breakdown of numbers under 100), and now 33 is the smallest such number.

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