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 A222454 #6 Jul 23 2025 02:36:47 %S A222454 4,23,194,1722,16440,161779,1752892,18608623,201223272,2201719251, %T A222454 24272631638,268705232398,2985516009592,33280348746620, %U A222454 371933566446760,4165471546299038,46738884729278494,525315130609406149 %N A222454 Number of nX6 0..1 arrays with exactly floor(nX6/2) elements unequal to at least one horizontal, vertical or antidiagonal neighbor, with new values introduced in row major 0..1 order. %C A222454 Column 6 of A222456 %H A222454 R. H. Hardin, <a href="/A222454/b222454.txt">Table of n, a(n) for n = 1..71</a> %e A222454 Some solutions for n=4 %e A222454 ..0..0..0..0..0..0....0..0..0..0..0..0....0..0..1..1..1..1....0..1..0..1..1..1 %e A222454 ..1..1..0..0..0..0....0..0..0..0..0..0....0..0..1..1..1..0....1..1..1..1..1..1 %e A222454 ..1..1..1..0..0..0....0..0..1..0..0..0....1..1..1..1..1..1....1..1..1..1..1..0 %e A222454 ..1..1..1..0..0..0....0..0..1..1..1..1....1..1..1..1..1..1....1..1..1..1..0..0 %K A222454 nonn %O A222454 1,1 %A A222454 _R. H. Hardin_ Feb 20 2013