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 A222513 #6 Jul 23 2025 02:42:41 %S A222513 0,8,87,497,2066,17674,81537,800040,3877847,39636760,197167116, %T A222513 2044535652,10266459303,107207411996,541084890084,5674279900642, %U A222513 28738733251005,302282496834886,1535249200603440,16185756541061498 %N A222513 Number of 5Xn 0..1 arrays with exactly floor(5Xn/2) elements unequal to at least one horizontal, diagonal or antidiagonal neighbor, with new values introduced in row major 0..1 order. %C A222513 Row 5 of A222509 %H A222513 R. H. Hardin, <a href="/A222513/b222513.txt">Table of n, a(n) for n = 1..42</a> %e A222513 Some solutions for n=3 %e A222513 ..0..0..0....0..0..0....0..0..0....0..0..1....0..0..0....0..0..0....0..0..0 %e A222513 ..0..0..0....0..0..1....0..0..0....0..0..0....1..0..0....0..0..0....1..1..0 %e A222513 ..1..0..0....0..0..0....1..0..0....1..0..1....1..1..1....0..0..1....1..1..1 %e A222513 ..1..0..0....0..0..0....0..0..1....0..0..0....1..1..1....1..1..1....1..1..1 %e A222513 ..1..0..0....0..0..1....0..0..1....0..0..0....1..1..1....1..1..1....1..1..1 %K A222513 nonn %O A222513 1,2 %A A222513 _R. H. Hardin_ Feb 23 2013