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 A260743 #6 Sep 24 2015 01:38:22 %S A260743 0,1,10,20,100,101,200,220,300,310,1000,1001,1010,1020,2000,2001,2200, %T A260743 2300,3000,3020,3100,3300,4000,4010,4100,4200,10000,10001,10010,10020, %U A260743 10100,10101,10200,10220,10300,10310,20000,20001,20010,20020,22000,22001,23000,23020,24000,24010,30000,30001,30200,30300,31000,31001,33000,33300,34000,34200,40000,40020,40100,40300,41000,41020,42000,42300 %N A260743 Sequence A261220 shown in factorial base: a(n) = A007623(A261220(n)). %F A260743 a(n) = A007623(A261220(n)). %o A260743 (Scheme) (define (A260743 n) (A007623 (A261220 n))) %Y A260743 Cf. A007623, A261220. %Y A260743 Cf. also A060495, A060496, A060498, A060499. %Y A260743 Subsequence: A014417. %K A260743 nonn,base %O A260743 0,3 %A A260743 _Antti Karttunen_, Aug 26 2015