Very cool. I thought to myself, before clicking on the article, "this is Hacker News, so its probably some interesting number theoretic sieve... but then again there are a lot of people who like to cook so maybe its some kind of novel mechanical sieve". So it was quite satisfying to see discover that it was BOTH in some sense.
"Lehmer sieves were very fast, in one particular case factoring 2^93 + 1 in 3 seconds."<p>Impressive. I wondered how fast my computer could do it. Here's the GNU coreutils factor:<p><pre><code> $ time factor 9903520314283042199192993793
9903520314283042199192993793: 3 3 529510939 715827883 2903110321
real 0m0.007s
user 0m0.004s
sys 0m0.000s
</code></pre>
Still impressive. This led me down factor's documentation to the Pollard Rho algorithm: <a href="http://en.wikipedia.org/wiki/Pollard%27s_rho_algorithm" rel="nofollow">http://en.wikipedia.org/wiki/Pollard%27s_rho_algorithm</a>