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 A282641 #6 Feb 28 2017 04:10:16 %S A282641 4,11,27,76,201,537,1444,3859,10339,27692,74145,198577,531780,1424091, %T A282641 3813739,10213132,27350713,73245065,196149732,525287779,1406717235, %U A282641 3767179500,10088482321,27016889761,72351054724,193755653291 %N A282641 Number of nX2 0..1 arrays with no 1 equal to more than one of its king-move neighbors. %C A282641 Column 2 of A282647. %H A282641 R. H. Hardin, <a href="/A282641/b282641.txt">Table of n, a(n) for n = 1..210</a> %F A282641 Empirical: a(n) = a(n-1) +3*a(n-2) +4*a(n-3). %F A282641 G.f.: -x*(4+7*x+4*x^2)/(-1+x+3*x^2+4*x^3) . - _R. J. Mathar_, Feb 28 2017 %e A282641 Some solutions for n=4 %e A282641 ..0..0. .0..0. .0..0. .1..1. .0..0. .0..1. .0..1. .0..1. .1..1. .0..0 %e A282641 ..1..0. .0..1. .0..1. .0..0. .0..0. .1..0. .0..0. .0..1. .0..0. .0..0 %e A282641 ..1..0. .0..1. .0..0. .0..0. .0..1. .0..0. .0..0. .0..0. .0..1. .0..0 %e A282641 ..0..0. .0..0. .1..0. .0..1. .0..0. .0..0. .1..0. .1..0. .0..0. .0..1 %Y A282641 Cf. A282647. %K A282641 nonn %O A282641 1,1 %A A282641 _R. H. Hardin_, Feb 20 2017