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 A140309 #4 Mar 31 2012 12:35:07 %S A140309 1,2,16,466,51512,21425198,32840182186,188637643581570, %T A140309 4048457379398984078,323937479341259299455434, %U A140309 96758393657902322435446080112 %N A140309 Number of n X n binary matrices containing no more than six 1s in any 3 X 3 sub-block. %Y A140309 Cf. A139810. %K A140309 nonn %O A140309 0,2 %A A140309 _R. H. Hardin_, May 27 2008