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 A184681 #9 Apr 14 2018 08:17:44 %S A184681 208,2384,21968,221968,2171152,21547024,212829840,2107074576, %T A184681 20846869136,206331811088,2041995275664,20210243538448, %U A184681 200025118846608,1979715148636944,19593894295270288,193927696142858256 %N A184681 Number of (n+1) X 5 binary arrays with every 2 X 2 subblock singular. %C A184681 Column 4 of A184686. %H A184681 R. H. Hardin, <a href="/A184681/b184681.txt">Table of n, a(n) for n = 1..200</a> %F A184681 Empirical: a(n) = 16*a(n-1) - 51*a(n-2) - 190*a(n-3) + 1058*a(n-4) - 848*a(n-5) - 1392*a(n-6) + 1536*a(n-7). %F A184681 Empirical g.f.: 16*x*(13 - 59*x - 348*x^2 + 1974*x^3 - 1692*x^4 - 2688*x^5 + 3072*x^6) / (1 - 16*x + 51*x^2 + 190*x^3 - 1058*x^4 + 848*x^5 + 1392*x^6 - 1536*x^7). - _Colin Barker_, Apr 14 2018 %e A184681 Some solutions for 3 X 5: %e A184681 ..1..1..1..0..0....1..0..0..0..1....0..0..1..0..0....0..0..0..0..1 %e A184681 ..0..0..0..0..0....1..0..0..0..0....0..0..0..0..0....1..1..0..0..0 %e A184681 ..1..1..0..1..0....1..0..1..1..1....1..0..0..0..1....0..0..0..1..1 %Y A184681 Cf. A184686 %K A184681 nonn %O A184681 1,1 %A A184681 _R. H. Hardin_, Jan 19 2011