Primes as a Service on Twitter

Our friend Andrew Eckford has spent some time over the holiday improving his Twitter bot Primes as a Service. He launched it in late Spring of 2016, but has added some new functionality over the holidays. It can be relatively handy if you need a quick answer during a class, taking an exam(?!), to settle a bet at a mathematics tea, while livetweeting a conference, or are hacking into your favorite cryptosystems.

General Instructions

Tweet a positive 9-digit (or smaller) integer at @PrimesAsAService. It will reply via Twitter to tell you if the number prime or not.

Some of the usable commands one can tweet to the bot for answers follow. (Hint: Click on the buttons with the tweet text to auto-generate the relevant Tweet.)

If you ask about a prime number with a twin prime, it should provide the twin.

Pro tip: You should be able to drag and drop any of the buttons above to your bookmark bar for easy access/use in the future.

Happy prime tweeting!

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Online Lectures in Information Theory

Where can I find good online lectures in information theory?(

There aren’t a lot of available online lectures on the subject of information theory, but here are the ones I’m currently aware of:



Fortunately, most are pretty reasonable, though vary in their coverage of topics. The introductory lectures don’t require as much mathematics and can probably be understood by those at the high school level with just a small amount of basic probability theory and an understanding of the logarithm.

The top three in the advanced section (they generally presume a prior undergraduate level class in probability theory and some amount of mathematical sophistication) are from professors who’ve written some of the most commonly used college textbooks on the subject. If I recall a first edition of the Yeung text was available via download through his course interface. MacKay’s text is available for free download from his site as well.

Feel free to post other video lectures or resources you may be aware of in the comments below.

Editor’s Update: With sadness, I’ll note that David MacKay died just days after this was originally posted.

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