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 A184678 #8 Jul 22 2025 09:40:52 %S A184678 10,128,3360,221968,31817360,10876933264,8344809419152, %T A184678 14901599172048528,60581954550463205264,567946901826257621019792, %U A184678 12186523252504462055625831824,601019440996497914601529636314768 %N A184678 Number of (n+1)X(n+1) binary arrays with every 2X2 subblock singular. %C A184678 Diagonal of A184686 %H A184678 R. H. Hardin, <a href="/A184678/b184678.txt">Table of n, a(n) for n = 1..15</a> %e A184678 Some solutions for 3X3 %e A184678 ..1..1..0....0..0..0....0..0..0....0..0..0....0..0..0....1..1..0....1..0..1 %e A184678 ..0..0..0....0..0..1....0..0..0....1..1..1....0..1..0....0..0..0....0..0..1 %e A184678 ..1..1..1....1..0..0....1..0..0....1..1..1....0..0..0....0..1..0....0..0..1 %K A184678 nonn %O A184678 1,1 %A A184678 _R. H. Hardin_ Jan 19 2011