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 A268999 #4 Feb 17 2016 07:30:45 %S A268999 32,379,4083,43512,421450,4097199,38241770,354861630,3233293149, %T A268999 29238488883,261801167468,2329097648405,20588801089961, %U A268999 181083224080162,1585346158237184,13824737077018333,120130562347636272 %N A268999 Number of 5Xn binary arrays with some element plus some horizontally or antidiagonally adjacent neighbor totalling two not more than once. %C A268999 Row 5 of A268995. %H A268999 R. H. Hardin, <a href="/A268999/b268999.txt">Table of n, a(n) for n = 1..210</a> %F A268999 Empirical: a(n) = 2*a(n-1) +97*a(n-2) +116*a(n-3) -2923*a(n-4) -10986*a(n-5) +4951*a(n-6) +72992*a(n-7) +36740*a(n-8) -223968*a(n-9) -159382*a(n-10) +423052*a(n-11) +256370*a(n-12) -539504*a(n-13) -176570*a(n-14) +450908*a(n-15) +6166*a(n-16) -217920*a(n-17) +57416*a(n-18) +45120*a(n-19) -25021*a(n-20) +562*a(n-21) +2089*a(n-22) -388*a(n-23) -31*a(n-24) +14*a(n-25) -a(n-26) %e A268999 Some solutions for n=4 %e A268999 ..0..0..0..0. .1..1..0..1. .1..0..0..1. .0..0..1..0. .0..1..0..0 %e A268999 ..1..1..0..1. .0..1..0..0. .0..1..0..0. .1..0..1..1. .0..0..0..0 %e A268999 ..0..1..0..0. .0..0..0..1. .1..0..0..1. .1..0..0..1. .0..0..0..1 %e A268999 ..0..0..1..0. .1..0..0..0. .1..0..0..1. .1..0..0..1. .1..0..0..1 %e A268999 ..0..0..0..1. .0..0..0..0. .0..0..0..1. .1..0..0..0. .0..0..0..1 %Y A268999 Cf. A268995. %K A268999 nonn %O A268999 1,1 %A A268999 _R. H. Hardin_, Feb 17 2016