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 A183320 #7 Jul 22 2025 08:49:09 %S A183320 55,523,9767,125103,1872913,25528515,360327392,4963103592,68795107993, %T A183320 947461430557,13049865962515,179449989707905,2465460224449227, %U A183320 33861928082629563,464723391441659251,6377980328407833025 %N A183320 Number of nX8 binary arrays with an element zero only if there are an even number of ones to its left and an even number of ones above it. %C A183320 Column 8 of A183322 %H A183320 R. H. Hardin, <a href="/A183320/b183320.txt">Table of n, a(n) for n = 1..200</a> %e A183320 Some solutions for 5X8 %e A183320 ..0..0..0..0..0..0..0..1....0..0..0..0..0..0..0..0....0..0..0..0..0..0..0..0 %e A183320 ..0..0..0..0..0..1..1..1....0..0..0..0..0..0..0..1....0..0..0..0..0..0..0..0 %e A183320 ..1..1..0..0..0..1..1..1....0..1..1..0..0..0..1..1....0..0..0..0..0..0..0..1 %e A183320 ..1..1..1..1..1..1..0..1....0..1..1..0..0..1..1..0....0..0..0..1..1..0..1..1 %e A183320 ..1..1..1..1..1..1..1..1....0..1..1..1..1..1..1..1....0..1..1..1..1..1..1..0 %K A183320 nonn %O A183320 1,1 %A A183320 _R. H. Hardin_ Jan 03 2011