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 A222450 #6 Jul 23 2025 02:36:19 %S A222450 0,0,2,7,10,23,64,175,400,983,2498,6409,15982,40282,102240,260590, %T A222450 662008,1685764,4301724,10996863,28122246,71995471,184507156, %U A222450 473312401,1215008846,3121272497,8023924572,20640895689,53127720534,136821537884 %N A222450 Number of nX2 0..1 arrays with exactly floor(nX2/2) elements unequal to at least one horizontal, vertical or antidiagonal neighbor, with new values introduced in row major 0..1 order. %C A222450 Column 2 of A222456 %H A222450 R. H. Hardin, <a href="/A222450/b222450.txt">Table of n, a(n) for n = 1..210</a> %e A222450 All solutions for n=4 %e A222450 ..0..0....0..0....0..1....0..0....0..0....0..0....0..0 %e A222450 ..1..1....0..0....0..0....0..1....0..0....0..0....0..0 %e A222450 ..1..1....0..1....0..0....1..1....0..0....0..0....1..1 %e A222450 ..1..1....1..1....0..0....1..1....1..0....1..1....1..1 %K A222450 nonn %O A222450 1,3 %A A222450 _R. H. Hardin_ Feb 20 2013