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 A183770 #9 Jun 06 2014 02:30:42 %S A183770 109824,5134924800,275588031713280,15664518350357381120, %T A183770 919029987874102029778944,55014538812191247245224181760, %U A183770 3339401594009138875954682737459200 %N A183770 1/32 the number of (2n+1) X 8 binary arrays with equal numbers of 2 X 2 subblocks with sum mod two being 0 and 1. %C A183770 Column 7 of A183772(2n). %H A183770 R. H. Hardin, <a href="/A183770/b183770.txt">Table of n, a(n) for n = 1..24</a> %e A183770 Some solutions for 3 X 8: %e A183770 ..0..0..0..0..0..1..0..0....0..0..0..0..0..1..0..1....0..0..0..0..0..0..1..1 %e A183770 ..1..0..1..0..0..1..0..1....0..0..0..0..0..0..0..0....1..0..1..1..0..1..1..1 %e A183770 ..1..0..1..0..1..0..0..0....1..0..1..1..1..0..1..1....0..1..1..1..0..1..1..0 %K A183770 nonn %O A183770 1,1 %A A183770 _R. H. Hardin_, Jan 06 2011