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 A207062 #9 Jul 22 2025 19:59:34 %S A207062 2,16,102,720,6398,54684,468348,4356936,41716708,403445900,4037337213, %T A207062 41571957024,435311467198,4653843868560,50835606848268, %U A207062 564791240516000,6378296516533122,73247208566761530,853936849893078000 %N A207062 Number of n X n 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 0 1 and 1 0 1 vertically. %C A207062 Diagonal of A207068 %H A207062 R. H. Hardin, <a href="/A207062/b207062.txt">Table of n, a(n) for n = 1..26</a> %e A207062 Some solutions for n=4 %e A207062 ..0..0..0..0....1..0..0..0....1..1..0..1....1..1..0..0....0..1..1..0 %e A207062 ..1..1..0..1....1..1..0..0....0..0..0..0....1..0..0..0....0..1..1..1 %e A207062 ..1..0..0..0....1..0..0..0....0..0..0..0....0..0..0..0....0..1..1..1 %e A207062 ..0..0..0..0....1..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0 %K A207062 nonn %O A207062 1,1 %A A207062 _R. H. Hardin_ Feb 14 2012