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 A222286 #6 Jul 23 2025 02:28:41 %S A222286 3,11,35,208,1125,6619,40321,250681,1569385,9860229,62350467, %T A222286 395971584,2523482587,16126203359,103311906743,663339238220, %U A222286 4267302505247,27498492193747,177468748791963,1146905501859999,7421110682709531 %N A222286 Number of nX4 0..1 arrays with exactly floor(nX4/2) elements unequal to at least one horizontal or vertical neighbor, with new values introduced in row major 0..1 order. %C A222286 Column 4 of A222290 %H A222286 R. H. Hardin, <a href="/A222286/b222286.txt">Table of n, a(n) for n = 1..136</a> %e A222286 Some solutions for n=4 %e A222286 ..0..0..0..0....0..0..0..0....0..0..0..0....0..0..1..1....0..1..1..1 %e A222286 ..0..0..0..0....0..0..0..0....0..0..1..0....0..1..1..1....1..0..1..1 %e A222286 ..0..0..1..1....0..0..1..1....0..0..0..0....0..0..1..1....0..1..1..1 %e A222286 ..1..1..1..1....0..0..1..0....1..0..0..0....0..1..1..1....1..1..1..1 %K A222286 nonn %O A222286 1,1 %A A222286 _R. H. Hardin_ Feb 14 2013