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 A169904 #9 Oct 04 2012 10:29:13 %S A169904 405,429,441,461,489,501,504,506,509,605,621,649,669,681,40401,40601, %T A169904 42041,42229,44021,44869,46081,46849,48061,48289,50501,50509,60409, %U A169904 60609,62049,62821,64029,64261,66089,66241,68069,68881 %N A169904 Carryless squares of carryless primes (cf. A169887). %H A169904 David Applegate, Marc LeBrun and N. J. A. Sloane, <a href="http://neilsloane.com/doc/carry1.pdf">Carryless Arithmetic (I): The Mod 10 Version</a> %H A169904 <a href="/index/Ca#CARRYLESS">Index entries for sequences related to carryless arithmetic</a> %K A169904 nonn,base %O A169904 1,1 %A A169904 _David Applegate_, _Marc LeBrun_ and _N. J. A. Sloane_, Jul 11 2010