...

On 6/5/06, Jason Holt <jason@lunkwill.org> wrote:

...

The number paintings inspired me to do some artwork of my own: http://lunkwill.org/tmp/mystery.png Any guesses what the plot represents?

Collatz problem?

Yes indeed, showing the number of steps to reach 1, log-scaled in both x and y, for n up to a billion.

I assume that is sequence A006577 in the OEIS, and indeed if you click on "graph" there you see a somewhat similar picture (look at the second plot). Indeed, many classic sequences have dramatic graphs - see e.g. A005132, or Pascal's triangle A007318. Note that you can usually get to an entry like A006577 simply by typing A006577 in the URL window (!) of your broswer. It is also amusing to listen to some of these sequences - see the "Listen" button at the foot of the OEIS pages. Neil Sloane