Article 28466 of rec.puzzles:
From: hoey@aic.nrl.navy.mil (Dan Hoey)
Newsgroups: rec.puzzles
Subject: Re: More Number Puzzlers [ spoiler ]
Supersedes: <HOEY.95May15122901@sun13.aic.nrl.navy.mil>
Date: 15 May 1995 22:10:33 GMT
Organization: Navy Center for Artificial Intelligence
In-reply-to: spurdy@pomona.edu's message of 13 May 95 11:00:35 PDT

spurdy@pomona.edu writes:

> Find a number whose digits when taken as a string of one digit
> numbers will represent the powers of the prime factorization of the
> original number.  The factorization must be listed in order,
> including every prime for which there is a digit.

> As this is poorly phrased, I will demonstrate a close answer.
> If I were allowed to begin at the ones digit and progress backward,
> 12 would be correct, as it is 3^1 * 2^2.

So, when you say "in order", you mean in big-endian order.  The
example with 12 is also "in order"--it's just in little-endian order.

This notice has been brought to you by the truth-in-endianism
guild.

Spoiler:
^L
According to computer search, the first one is 81312000.
There are no others up to 10^19.
There are also no little-endian solutions between 13 and 10^19.

This is an excellent exercise in finding ways to speed up an algorithm
that's running just a tad too slow....

Dan
Hoey@AIC.NRL.Navy.Mil