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 A282991 #6 Mar 02 2017 12:31:40 %S A282991 7,33,163,803,3971,19587,96693,477297,2355925,11629027,57401721, %T A282991 283338413,1398577069,6903468049,34075967931,168201202963, %U A282991 830252119477,4098178655825,20228877377719,99851059281979,492871346862069 %N A282991 Number of nX3 0..1 arrays with no 1 equal to more than one of its horizontal and vertical neighbors. %C A282991 Column 3 of A282996. %H A282991 R. H. Hardin, <a href="/A282991/b282991.txt">Table of n, a(n) for n = 1..210</a> %F A282991 Empirical: a(n) = 2*a(n-1) +10*a(n-2) +20*a(n-3) +13*a(n-4) -9*a(n-5) -10*a(n-6) -3*a(n-7) -a(n-8) +a(n-9). %F A282991 Empirical: G.f.: -x*(7+19*x+27*x^2+7*x^3-16*x^4-11*x^5-3*x^6+x^8) / ( (1+x)*(x^8-2*x^7-x^6-9*x^5+13*x^3+7*x^2+3*x-1) ). - _R. J. Mathar_, Mar 02 2017 %e A282991 Some solutions for n=5 %e A282991 ..0..0..1. .0..1..0. .0..0..0. .1..0..1. .0..1..0. .1..0..0. .1..0..0 %e A282991 ..1..0..1. .0..1..0. .1..0..0. .0..0..1. .1..0..1. .0..0..1. .0..0..0 %e A282991 ..0..0..0. .1..0..1. .0..1..0. .0..1..0. .1..0..0. .0..1..0. .0..1..0 %e A282991 ..0..1..0. .1..0..1. .0..1..0. .0..1..0. .0..1..1. .0..1..0. .0..0..0 %e A282991 ..1..0..0. .0..0..0. .1..0..1. .1..0..0. .0..0..0. .1..0..1. .0..0..1 %Y A282991 Cf. A282996. %K A282991 nonn %O A282991 1,1 %A A282991 _R. H. Hardin_, Feb 26 2017