This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A112512 #1 Sep 21 2005 03:00:00
%S A112512 2,12,1112,3112,132112,311322,232122,421311,14123113,41141223,
%T A112512 24312213,32142321,23322114,32232114,23322114,32232114,23322114,
%U A112512 32232114
%N A112512 Say what you see in previous term, same as A063850, but starting with 2.
%C A112512 Eventually periodic, eventually identical (to a shift of) A063850.
%o A112512 (Perl) #!/usr/bin/perl -l use strict; use warnings; die "Usage: $0 <number> " unless @ARGV==1; $_=shift; { print; my (%cnt, %saw); $cnt{$_}++ for /./g; s/./ $saw{$&}++ ? '' : $cnt{$&} . $& /ge; <>, redo; } __END__
%Y A112512 Cf. A005150, A005151, A063850, A112512-A112516.
%K A112512 base,easy,nonn
%O A112512 1,1
%A A112512 Michele Dondi (blazar(AT)lcm.mi.infn.it), Sep 09 2005