## Fractal Brownian Tree

@fawnpnguyen whoa. Need to try and make this. — Dan Anderson (@dandersod) June 4, 2013 I started off and used VPython to create the fractal, but it was slow and buggy. Here’s a movie of my first attempt. When you click you create a new “seed” for the fractal to start.  So I rewrote it […]

## Calculate Pi with Python

Intro to Computer programming worked at calculating digits of pi today. The actual algorithms aren’t too bad, but getting more than the standard number of digits from a double is a bit trickier. Here’s a program that calculates pi using: Bailey–Borwein–Plouffe formula Bellard’s formula and Chudnovsky algorithm Holy smokes is Chudnovsky algorithm’s fast! Plouff Bellard Chudnovsky Iteration […]

## Powers of 2 without a Zero

2^86 is largest known pwr of 2 that does not contain 0.What about other digits?Does each non-zero digit occur inf often among the pwrs of 2? — James Tanton (@jamestanton) March 6, 2013 Interesting. The Intro to Programming Students gave a crack at this one; and after 30 minutes all were close and half had […]

## Reducing Prime

Number theory nugget: 357686312646216567629137 is a prime number which remains prime after removing any number of digits from the left side! — Maths World UK (@MathsWorldUK) March 4, 2013 Otherwise known as left-truncating primes with every suffix prime and no digit are zero. Here is the whole sequence. It was proven that 357686312646216567629137 is the last […]

## Bret Victor’s Learnable Programming

Bret Victor (Inventing on Principle) wrote an excellent essay on Learnable Programming. If you have any interest in how people learn computer programming best, or how people learn in general, then go read it. Now. Shoo. And you probably want to read it on a computer; there are several short videos to accompany the text. This essay […]

## Move The Turtle (iOS)

Move The Turtle. The “game” portion of this app is pretty simple, but it comes with a programming interface which is very easy to get into. Fun stuff. After 10 minutes of tweaking: