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 A222285 #6 Jul 23 2025 02:28:33 %S A222285 0,4,4,35,83,532,1427,8540,23798,143594,405187,2455279,6993039, %T A222285 42590466,121981025,745909396,2145554406,13161790760,37983541068, %U A222285 233613349710,675981684148,4166412530876,12082238135283,74601934076542 %N A222285 Number of nX3 0..1 arrays with exactly floor(nX3/2) elements unequal to at least one horizontal or vertical neighbor, with new values introduced in row major 0..1 order. %C A222285 Column 3 of A222290 %H A222285 R. H. Hardin, <a href="/A222285/b222285.txt">Table of n, a(n) for n = 1..210</a> %e A222285 Some solutions for n=4 %e A222285 ..0..0..0....0..1..1....0..0..1....0..0..0....0..0..0....0..0..0....0..1..0 %e A222285 ..1..1..0....1..1..1....0..0..0....0..0..0....0..0..0....0..0..0....1..0..0 %e A222285 ..1..1..1....1..1..1....0..0..0....1..0..0....1..0..0....1..0..1....0..0..0 %e A222285 ..1..1..1....1..1..0....1..0..0....1..1..1....0..1..0....1..1..1....0..0..0 %K A222285 nonn %O A222285 1,2 %A A222285 _R. H. Hardin_ Feb 14 2013