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 A240653 #6 Jul 23 2025 11:05:29 %S A240653 1,6,43,352,2456,16629,118863,863435,6296517,46082534,337974465, %T A240653 2482292322,18247326003,134198700821,987225183085,7263640120506, %U A240653 53448292499747,393312676324283,2894385928048833,21300183245716512 %N A240653 Number of nX5 0..1 arrays with no element equal to exactly one horizontal or vertical neighbor, with new values 0..1 introduced in row major order. %C A240653 Column 5 of A240656 %H A240653 R. H. Hardin, <a href="/A240653/b240653.txt">Table of n, a(n) for n = 1..210</a> %e A240653 Some solutions for n=4 %e A240653 ..0..0..1..1..0....0..0..0..0..0....0..1..1..1..1....0..1..1..0..0 %e A240653 ..0..0..1..1..1....0..0..0..1..0....1..1..1..1..1....1..1..1..0..0 %e A240653 ..1..1..0..1..1....0..1..0..0..0....1..1..0..1..1....1..1..1..0..0 %e A240653 ..1..1..1..1..0....0..0..0..0..0....1..1..1..1..1....0..1..1..0..0 %K A240653 nonn %O A240653 1,2 %A A240653 _R. H. Hardin_, Apr 09 2014