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 A112515 #1 Sep 21 2005 03:00:00
%S A112515 5,15,1115,3115,132115,31131215,23411215,2213143115,2241231415,
%T A112515 3224311315,3322143115,3322311415,3322311415,3322311415,3322311415,
%U A112515 3322311415,3322311415
%N A112515 Say what you see in previous term, same as A063850 but starting with 5.
%o A112515 (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 A112515 Cf. A005150, A005151, A063850, A112512-A112515.
%K A112515 base,easy,nonn
%O A112515 1,1
%A A112515 Michele Dondi (blazar(AT)lcm.mi.infn.it), Sep 09 2005