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 A189774 #7 Nov 30 2021 19:02:15 %S A189774 15,225,3375,37976,418550,4461435,48633913,530389481,5817065520, %T A189774 63680392402,697353409375,7631111846379,83521134087527, %U A189774 914046929969572,10004056595349672,109490279695417318,1198342710234669673 %N A189774 Number of n X 4 binary arrays without the pattern 1 0 0 1 diagonally, vertically or horizontally. %C A189774 Column 4 of A189779. %H A189774 R. H. Hardin, <a href="/A189774/b189774.txt">Table of n, a(n) for n = 1..200</a> %e A189774 Some solutions for 5 X 4 %e A189774 ..0..0..0..0....0..0..0..0....0..0..0..1....0..0..0..1....0..0..1..0 %e A189774 ..0..1..0..1....1..1..1..1....0..0..0..1....1..1..0..0....1..0..1..0 %e A189774 ..0..0..0..1....0..1..0..1....0..0..0..1....0..1..1..0....1..0..1..0 %e A189774 ..1..1..0..0....0..0..1..1....0..1..0..1....1..1..1..0....0..0..1..0 %e A189774 ..0..1..0..1....0..1..1..1....0..1..0..0....1..0..0..0....0..1..0..1 %Y A189774 Cf. A189779. %K A189774 nonn %O A189774 1,1 %A A189774 _R. H. Hardin_ Apr 27 2011