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 A222452 #6 Jul 23 2025 02:36:32 %S A222452 3,7,17,101,426,1722,8483,46788,246899,1263032,6568737,34802586, %T A222452 184657217,976867173,5178449568,27557967928,146974586179,784645686795, %U A222452 4194027064034,22450449919571,120330101083792,645608703621958 %N A222452 Number of nX4 0..1 arrays with exactly floor(nX4/2) elements unequal to at least one horizontal, vertical or antidiagonal neighbor, with new values introduced in row major 0..1 order. %C A222452 Column 4 of A222456 %H A222452 R. H. Hardin, <a href="/A222452/b222452.txt">Table of n, a(n) for n = 1..204</a> %e A222452 Some solutions for n=4 %e A222452 ..0..0..1..1....0..0..0..0....0..0..1..1....0..0..0..0....0..0..0..0 %e A222452 ..0..0..1..1....0..0..0..0....0..0..1..1....1..1..0..0....0..0..0..0 %e A222452 ..0..0..1..1....1..1..1..1....0..0..0..0....0..0..0..0....1..1..0..0 %e A222452 ..0..0..1..1....1..1..1..1....0..0..0..0....0..0..0..0....1..1..0..0 %K A222452 nonn %O A222452 1,1 %A A222452 _R. H. Hardin_ Feb 20 2013