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 A208691 #8 Jul 05 2018 13:54:39 %S A208691 14,196,490,3430,12096,66094,269766,1331988,5795314,27403166, %T A208691 122618944,569030406,2577715070,11864806436,54038278042,247841874742, %U A208691 1131464944960,5181256121790,23678302787734,108354576646260,495403870286178 %N A208691 Number of 5 X n 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 1 1 and 1 0 1 vertically. %C A208691 Row 5 of A208688. %H A208691 R. H. Hardin, <a href="/A208691/b208691.txt">Table of n, a(n) for n = 1..210</a> %F A208691 Empirical: a(n) = a(n-1) + 17*a(n-2) + 4*a(n-3) - 32*a(n-4). %F A208691 Empirical g.f.: 14*x*(1 + 13*x + 4*x^2 - 32*x^3) / (1 - x - 17*x^2 - 4*x^3 + 32*x^4). - _Colin Barker_, Jul 05 2018 %e A208691 Some solutions for n=4: %e A208691 ..1..1..1..1....1..1..1..1....1..0..1..1....1..1..0..1....1..0..1..0 %e A208691 ..1..0..1..1....0..1..0..1....1..0..1..1....0..1..1..0....1..1..1..0 %e A208691 ..1..0..1..1....0..1..0..0....1..0..1..0....0..1..0..0....1..0..1..1 %e A208691 ..1..1..1..1....1..1..1..0....1..1..1..0....0..1..0..0....1..0..1..0 %e A208691 ..1..0..1..0....0..1..0..1....1..0..1..0....0..1..0..1....1..1..0..0 %Y A208691 Cf. A208688. %K A208691 nonn %O A208691 1,1 %A A208691 _R. H. Hardin_, Mar 01 2012