## 14 August 2007

### Primeshooter

Primeshooter, from 1729.com. You shoot numbers with their prime factors; when you hit a number with one of its prime factors (2, 3, 5, 7, 11, 13, 17, or 19) it is divided by that number. Once you reduce a number to a prime, you can hit it with a "prime" bullet that makes it go away; numbers also go away if you successfully get them down to 1. You lose a life if a number hits you; if a number reaches the bottom of the screen without getting down to 1 it reappears at the top. Sometimes (I don't know when) it appears in a bright red box, in which case you'll lose a life if it reaches the bottom. Sometimes you get an extra life.

I got a score of 834 (= 2 × 3 × 139, although that's irrelevant), which means I successfully shot at 834 prime numbers. I don't recommend trying to beat me, because even if you succeed you will lose about thirty-five minutes of your real life.

The rest of the web page looks kind of fun, too.

An exercise for the reader: why is it fitting that this is on 1729.com?

John Armstrong said...

An exercise for the reader: why is it fitting that this is on 1729.com?

Nah, too easy. I'll leave it to someone who hasn't heard that story.

Kea said...

But John, this isn't just about the story of the taxicab: its also about the mathematics of elliptic curves (for example).

dan said...

You know, that coincidence pops up in Proof, too.