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 A206881 #7 Jul 22 2025 19:46:11 %S A206881 37,1369,22412,321393,5179587,87541530,1455584860,23905464739, %T A206881 393067971811,6480684234921,106874325247350,1761571690252448, %U A206881 29031364788581620,478487481722152310,7886646984790650669 %N A206881 Number of nX6 0..1 arrays avoiding 0 1 0 horizontally and 1 0 1 vertically. %C A206881 Column 6 of A206883 %H A206881 R. H. Hardin, <a href="/A206881/b206881.txt">Table of n, a(n) for n = 1..210</a> %e A206881 Some solutions for n=4 %e A206881 ..0..1..1..1..0..0....0..0..0..1..1..0....1..1..1..0..0..0....0..1..1..1..0..0 %e A206881 ..1..0..0..1..1..0....0..0..0..0..0..1....0..0..1..1..1..0....1..0..1..1..1..0 %e A206881 ..0..0..0..1..1..0....1..1..1..0..0..1....0..0..0..0..1..1....1..0..0..0..1..1 %e A206881 ..0..1..1..0..1..1....0..1..1..0..1..1....0..0..0..0..1..1....1..1..0..0..0..1 %K A206881 nonn %O A206881 1,1 %A A206881 _R. H. Hardin_ Feb 13 2012