Numberphile

If you are like me then you will like http://www.youtube.com/user/Vihart (squee! ♥)

and you will have seen Numberphile... which so far has not been as good as The Singing Banana, until today! (So I declare!)

For me today's episode of numberphile is as cool as I had been hoping they would be.
( I hope that they have just got into their stride.)

The previous episodes have been, for me, between so-so and hmmm, (so worth seeing, but not worth a thumbs up [0].)

If I had to do an episode then mine would be 15 and I would talk about black-hole numbers [1].

I wonder if they would let me pick 1234, but then talk about 1,2,3,4 and trying to create every number from [1..100] just using each of those digits once. i.e.

1+2+3+4   =10 (99 left to find),
(1+2)(3+4)=14  (98) left to find.

Many years ago my friend Shevek wrote, (in 3194 bytes of perl) a program that searched for all possibilities. Before that my friend Nico and I had found most of them by hand.

(If you get stuck then you can ask me for help.)

[0] It would be nice to have some granularity. Did I like the production; Did I like the relevance to what I was looking for? (Come on 'The Internet' not all of us are undergrads ;-)

[1] Recurse through { The sum of the divisors of a natural number } => 15