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 A189156 #7 Jul 22 2025 11:34:57 %S A189156 15,225,3375,37976,424401,4597967,48460966,507947896,5289780940, %T A189156 54890361712,568739622865,5886254888757,60885233141712, %U A189156 629580674428109,6508873299252199,67284551942503294,695503798053171610 %N A189156 Number of nX4 binary arrays without the pattern 0 0 1 1 diagonally, vertically or horizontally. %C A189156 Column 4 of A189161 %H A189156 R. H. Hardin, <a href="/A189156/b189156.txt">Table of n, a(n) for n = 1..200</a> %e A189156 Some solutions for 5X4 %e A189156 ..0..0..0..1....0..0..0..1....0..0..1..0....0..0..0..1....0..0..0..1 %e A189156 ..1..1..1..0....1..1..0..0....1..1..0..1....1..1..0..1....1..1..0..1 %e A189156 ..0..0..0..1....1..0..1..1....1..1..1..0....0..1..0..1....0..1..1..0 %e A189156 ..0..0..0..0....0..0..0..1....0..1..0..1....1..1..1..1....1..1..0..1 %e A189156 ..1..1..1..1....0..1..1..0....0..1..1..0....0..1..0..0....0..1..0..0 %K A189156 nonn %O A189156 1,1 %A A189156 _R. H. Hardin_ Apr 17 2011