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 A064477 #1 May 16 2003 03:00:00 %S A064477 220,221,1220,1221,2200,2201,2210,2211,10220,10221,11220,11221,12200, %T A064477 12201,12210,12211,22000,22001,22010,22011,22100,22101,22110,22111, %U A064477 22220,22221,23020,23021,33300,33301,33310,33311,100220,100221,101220 %N A064477 A064637 converted to factorial base. %K A064477 nonn %O A064477 0,1 %A A064477 Antti Karttunen, Oct 03 2001