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 A206869 #7 Jul 22 2025 19:45:09 %S A206869 44,1936,31529,502864,8942469,159327093,2805723059,49382253588, %T A206869 870161983686,15335126811127,270230133940648,4761777405210821, %U A206869 83908473333577949,1478577785507810905,26054511301483619894 %N A206869 Number of nX6 0..1 arrays avoiding 0 0 0 horizontally and 1 0 1 vertically. %C A206869 Column 6 of A206871 %H A206869 R. H. Hardin, <a href="/A206869/b206869.txt">Table of n, a(n) for n = 1..210</a> %e A206869 Some solutions for n=4 %e A206869 ..1..0..1..1..1..0....1..0..1..1..1..0....0..1..0..1..1..1....0..1..1..0..1..1 %e A206869 ..0..1..0..1..1..0....0..1..1..1..0..1....0..0..1..1..0..1....0..1..0..1..1..0 %e A206869 ..0..1..0..1..0..1....0..0..1..0..0..1....1..0..1..0..0..1....1..0..0..1..0..0 %e A206869 ..0..0..1..1..0..0....0..0..1..0..1..0....0..1..0..0..1..0....0..0..1..1..0..0 %K A206869 nonn %O A206869 1,1 %A A206869 _R. H. Hardin_ Feb 13 2012