Look and say is a simple sequence generator: for
example start with 1 and describe it as one one,
which might be written 11 which in turn could be described
as two ones, which might be written 21 which in
turn could be described as one two, one one, which might
be written 1211... etc. There is more
information below, but this page provides a JavaScript
function written by Henry Bottomley
for extending the sequence. Just click on the Look and Write
button. You can also change the starting point, just by typing
something into the large box.

More information

John Conway (formerly a professor at Cambridge and now at
Princeton) has shown that the asymptotic rate of growth of the
length of the string is just over 1.3. He has written about the
sequence and some similarities with molecular and atomic
chemistry with Richard Guy in The
Book of Numbers. "Audioactive" is a pun based on
the Look and Say method and radioactive elements. Online
information includes Stephen Finch's page for Mathsoft on Conway's
Constant, my pages on the evolution of
the 92 elements and their seven
possible orderings, Mario Hilgemeier's writings in Fractal Horizons,
on audioactive decay and fractals, and a number of pages (only
sometimes available) from Eric Weisstein's CRC Concise
Encyclopedia of Mathematics on Look
and Say Sequence, Conway's
Constant, Conway
Sequence, and Cosmological
Theorem.