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 A295525 #8 Feb 21 2018 14:40:31 %S A295525 2,10,29,87,280,876,2735,8583,26900,84274,264107,827651,2593568, %T A295525 8127490,25469197,79812833,250109752,783769936,2456102483,7696696911, %U A295525 24119166438,75582316528,236852570799,742225734425,2325915393694,7288729246884 %N A295525 Number of n X 2 0..1 arrays with each 1 horizontally or vertically adjacent to 1, 2 or 4 1s. %C A295525 Column 2 of A295531. %H A295525 R. H. Hardin, <a href="/A295525/b295525.txt">Table of n, a(n) for n = 1..210</a> %F A295525 Empirical: a(n) = 2*a(n-1) + 2*a(n-2) + 5*a(n-3) - a(n-5) - a(n-6). %F A295525 Empirical g.f.: x*(2 + 6*x + 5*x^2 - x^3 - 2*x^4 - x^5) / (1 - 2*x - 2*x^2 - 5*x^3 + x^5 + x^6). - _Colin Barker_, Feb 21 2018 %e A295525 Some solutions for n=5: %e A295525 ..1..1. .1..1. .1..1. .1..1. .1..0. .0..0. .0..0. .0..0. .0..1. .1..1 %e A295525 ..1..0. .1..0. .1..1. .0..0. .1..0. .1..1. .1..1. .1..1. .0..1. .0..1 %e A295525 ..1..1. .0..0. .0..0. .1..1. .1..0. .1..0. .0..0. .0..0. .0..0. .0..1 %e A295525 ..0..1. .0..1. .1..0. .0..1. .1..1. .1..0. .1..1. .1..1. .1..0. .0..0 %e A295525 ..0..1. .1..1. .1..1. .0..1. .0..0. .0..0. .1..0. .1..1. .1..1. .1..1 %Y A295525 Cf. A295531. %K A295525 nonn %O A295525 1,1 %A A295525 _R. H. Hardin_, Nov 23 2017