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 A207424 #7 Jul 22 2025 20:24:54 %S A207424 25,625,5625,47089,444889,3892729,32936121,283215241,2427040225, %T A207424 20642505625,175841842225,1499143116025,12764120981481, %U A207424 108666218127481,925439613839521,7880177347151769,67093251777369801,571284105880558225 %N A207424 Number of nX6 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 0 1 0 vertically. %C A207424 Column 6 of A207426 %H A207424 R. H. Hardin, <a href="/A207424/b207424.txt">Table of n, a(n) for n = 1..210</a> %e A207424 Some solutions for n=4 %e A207424 ..0..1..1..1..1..0....0..0..1..1..1..0....0..1..1..0..1..1....1..1..1..1..1..1 %e A207424 ..1..0..1..1..0..0....0..0..1..1..0..0....1..0..1..1..1..1....1..1..1..1..0..1 %e A207424 ..1..1..0..1..1..0....0..0..1..1..1..0....1..1..1..1..1..1....1..1..1..1..1..0 %e A207424 ..1..1..0..1..1..0....0..0..1..1..1..0....1..1..0..1..1..1....1..1..1..0..1..1 %K A207424 nonn %O A207424 1,1 %A A207424 _R. H. Hardin_ Feb 17 2012