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 A189152 #8 Jul 22 2025 11:34:37 %S A189152 2,16,512,37976,8210464,4708773306,6787471566616,25828698626846656, %T A189152 247502169348575094540,6064620415913633106142608 %N A189152 Number of n X n binary arrays without the pattern 0 0 1 1 diagonally, vertically or horizontally. %C A189152 Diagonal of A189161 %e A189152 Some solutions for 4X4 %e A189152 ..0..0..0..0....0..1..0..1....0..1..1..0....0..1..1..1....1..1..1..0 %e A189152 ..0..0..0..0....1..0..0..1....1..1..0..0....0..1..0..1....1..1..0..0 %e A189152 ..0..1..0..1....1..0..0..1....0..0..0..1....1..1..1..0....0..1..1..0 %e A189152 ..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..1....0..0..1..0 %K A189152 nonn %O A189152 1,1 %A A189152 _R. H. Hardin_ Apr 17 2011