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 A268738 #4 Feb 12 2016 08:45:08 %S A268738 20,420,7831,128232,1971414,29134076,418632185,5894815754,81718671716, %T A268738 1119014223138,15171181272721,203998929406004,2724149465085496, %U A268738 36163754541884778,477648079847735215,6280858615510607492 %N A268738 Number of nX6 binary arrays with some 1 horizontally or vertically adjacent to some other 1 exactly once. %C A268738 Column 6 of A268740. %H A268738 R. H. Hardin, <a href="/A268738/b268738.txt">Table of n, a(n) for n = 1..210</a> %F A268738 Empirical: a(n) = 16*a(n-1) +60*a(n-2) -1148*a(n-3) -3346*a(n-4) +16272*a(n-5) +36588*a(n-6) -104246*a(n-7) -147989*a(n-8) +349140*a(n-9) +217324*a(n-10) -591448*a(n-11) -19320*a(n-12) +431032*a(n-13) -151921*a(n-14) -73194*a(n-15) +41684*a(n-16) +2552*a(n-17) -3594*a(n-18) +148*a(n-19) +100*a(n-20) -4*a(n-21) -a(n-22) %e A268738 Some solutions for n=4 %e A268738 ..0..0..0..0..1..0. .0..0..0..0..1..0. .1..0..0..0..0..1. .0..0..1..1..0..0 %e A268738 ..0..0..1..0..0..0. .0..1..0..0..0..0. .0..1..0..0..0..0. .0..1..0..0..1..0 %e A268738 ..1..0..0..0..0..0. .1..0..0..0..0..0. .1..0..0..1..0..0. .0..0..0..0..0..0 %e A268738 ..0..0..1..1..0..0. .1..0..1..0..1..0. .1..0..0..0..0..1. .0..0..0..0..0..1 %Y A268738 Cf. A268740. %K A268738 nonn %O A268738 1,1 %A A268738 _R. H. Hardin_, Feb 12 2016