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 A189901 #7 Jul 22 2025 11:55:45 %S A189901 28,784,21952,372850,6442436,101895401,1518596226,22333076803, %T A189901 319934642768,4537262993168,63834288477978,892671848458793, %U A189901 12444325266903474,173027620927389879,2402063580660811510 %N A189901 Number of nX5 binary arrays without the pattern 0 0 1 1 diagonally, vertically, antidiagonally or horizontally. %C A189901 Column 5 of A189905 %H A189901 R. H. Hardin, <a href="/A189901/b189901.txt">Table of n, a(n) for n = 1..200</a> %e A189901 Some solutions for 4X5 %e A189901 ..0..1..0..0..1....0..0..0..0..0....0..0..1..0..1....0..1..0..1..1 %e A189901 ..1..0..0..0..1....1..1..1..0..1....1..1..1..1..1....1..1..1..0..1 %e A189901 ..0..0..0..1..0....1..0..0..0..0....0..1..1..0..0....1..0..1..1..1 %e A189901 ..1..1..1..0..1....1..1..0..0..1....0..0..1..0..1....1..1..1..0..1 %K A189901 nonn %O A189901 1,1 %A A189901 _R. H. Hardin_ May 01 2011