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 A228753 #7 Sep 03 2013 23:52:29 %S A228753 13,289,6277,134440,2876170,61534448,1316714732,28177227352, %T A228753 602998827928,12904414518912,276160275058160,5909958226524512, %U A228753 126475877308730464,2706643227463513344,57923438257867988416,1239588830689830585216 %N A228753 Number of nX7 binary arrays with top left element equal to 1 and no two ones adjacent horizontally or antidiagonally. %C A228753 Column 7 of A228754 %H A228753 R. H. Hardin, <a href="/A228753/b228753.txt">Table of n, a(n) for n = 1..210</a> %F A228753 Empirical: a(n) = 34*a(n-1) -324*a(n-2) +1264*a(n-3) -2236*a(n-4) +1816*a(n-5) -624*a(n-6) +64*a(n-7) for n>9 %e A228753 Some solutions for n=4 %e A228753 ..1..0..1..0..0..0..0....1..0..0..1..0..0..1....1..0..1..0..0..0..0 %e A228753 ..0..0..1..0..0..0..1....0..0..0..1..0..0..1....1..0..1..0..0..0..1 %e A228753 ..0..0..0..1..0..0..1....0..0..0..0..1..0..1....0..0..0..1..0..0..1 %e A228753 ..0..0..0..0..1..0..1....1..0..0..0..0..0..0....1..0..0..1..0..0..0 %K A228753 nonn %O A228753 1,1 %A A228753 _R. H. Hardin_ Sep 02 2013