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 A228688 #7 Sep 01 2013 16:28:50 %S A228688 128,577,21305,176032,4008817,44171841,806190208,10258304689, %T A228688 168184756793,2301665823616,35784406285057,508094306671233, %U A228688 7692715116119040,111277331056067617,1662525457133097145 %N A228688 Number of 7Xn binary arrays with no two ones adjacent horizontally, diagonally or antidiagonally. %C A228688 Row 7 of A228683 %H A228688 R. H. Hardin, <a href="/A228688/b228688.txt">Table of n, a(n) for n = 1..210</a> %F A228688 Empirical: a(n) = 9*a(n-1) +184*a(n-2) -1201*a(n-3) -7155*a(n-4) +46048*a(n-5) +70745*a(n-6) -591673*a(n-7) -154744*a(n-8) +3207657*a(n-9) -715173*a(n-10) -7580648*a(n-11) +3369552*a(n-12) +7114920*a(n-13) -3800952*a(n-14) -1923264*a(n-15) +1083456*a(n-16) %e A228688 Some solutions for n=4 %e A228688 ..0..0..0..1....0..1..0..0....0..1..0..0....0..0..0..0....0..0..0..0 %e A228688 ..0..0..0..0....0..0..0..0....0..1..0..1....1..0..0..0....1..0..0..0 %e A228688 ..0..0..1..0....0..1..0..0....0..0..0..0....1..0..0..0....1..0..0..0 %e A228688 ..1..0..0..0....0..1..0..1....0..0..0..0....0..0..0..0....1..0..1..0 %e A228688 ..0..0..0..1....0..0..0..0....0..1..0..1....0..0..0..0....1..0..0..0 %e A228688 ..0..1..0..0....0..0..1..0....0..0..0..0....1..0..1..0....1..0..0..0 %e A228688 ..0..1..0..0....1..0..1..0....0..0..1..0....0..0..1..0....0..0..0..1 %K A228688 nonn %O A228688 1,1 %A A228688 _R. H. Hardin_ Aug 30 2013