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 A206888 #7 Jul 22 2025 19:46:56 %S A206888 65,4225,130828,3619683,88342972,2067672443,47015346159,1055711535814, %T A206888 23532283930933,522710080189316,11588335111405673,256664132470888238, %U A206888 5681796685012635460,125745518448573773703,2782522570829447521632 %N A206888 Number of nX7 0..1 arrays avoiding 0 1 0 horizontally and 1 0 0 vertically. %C A206888 Column 7 of A206889 %H A206888 R. H. Hardin, <a href="/A206888/b206888.txt">Table of n, a(n) for n = 1..210</a> %e A206888 Some solutions for n=4 %e A206888 ..0..1..1..1..0..0..0....0..1..1..1..0..0..1....0..0..0..0..0..1..1 %e A206888 ..1..0..0..1..1..0..0....0..0..1..1..1..1..0....1..1..1..0..0..0..1 %e A206888 ..0..1..1..1..0..0..0....0..1..1..1..1..1..1....0..0..1..1..1..1..0 %e A206888 ..1..1..1..0..1..1..0....0..1..1..1..0..1..1....1..1..0..0..1..1..1 %K A206888 nonn %O A206888 1,1 %A A206888 _R. H. Hardin_ Feb 13 2012