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 A057408 #12 Jul 19 2014 01:09:57 %S A057408 10,212,2530,22640,169906,1131904,6920388,39668532,216315230, %T A057408 1133876128,5757104542,28478125312,137854314576,655307492388, %U A057408 3067528095994,14171567365156,64732059542906,292778085749036 %N A057408 Number of self-avoiding polygons of area n with 3 (self-avoiding polygon) holes on square lattice (not allowing rotations). %H A057408 I. Jensen, <a href="/A057408/b057408.txt">Table of n, a(n) for n = 18..47</a> (from link below) %H A057408 I. Jensen, <a href="http://www.ms.unimelb.edu.au/~iwan/polygons/series/square.area.3hole.ser">More terms</a> %K A057408 nonn %O A057408 18,1 %A A057408 _N. J. A. Sloane_, Aug 30 2000