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 A189337 #7 Jul 22 2025 11:42:45 %S A189337 8,64,512,3375,21952,140608,912673,5929741,38614472,251239591, %T A189337 1634691752,10633486599,69173457625,449983383247,2927275422625, %U A189337 19042718961664,123878371625000,805862864751112,5242361459792813,34103003909455872 %N A189337 Number of nX3 binary arrays without the pattern 1 0 0 1 diagonally, vertically, antidiagonally or horizontally. %C A189337 Column 3 of A189343 %H A189337 R. H. Hardin, <a href="/A189337/b189337.txt">Table of n, a(n) for n = 1..200</a> %F A189337 Empirical: a(n) = 7*a(n-1) -41*a(n-3) +130*a(n-4) +81*a(n-6) -369*a(n-7) -73*a(n-8) -173*a(n-9) +243*a(n-10) +211*a(n-11) -77*a(n-12) +117*a(n-13) +81*a(n-14) +20*a(n-16) +13*a(n-17) +a(n-19) +a(n-20) %e A189337 Some solutions for 4X3 %e A189337 ..0..1..0....0..0..0....0..0..1....0..0..0....1..1..1....1..0..1....1..1..0 %e A189337 ..0..1..1....1..1..1....1..1..0....0..0..0....1..0..1....0..1..1....1..1..1 %e A189337 ..0..1..1....0..0..1....0..1..0....0..0..0....1..1..0....1..0..1....0..1..1 %e A189337 ..1..1..1....0..0..0....1..0..0....0..1..0....0..1..1....0..0..1....1..1..1 %Y A189337 A049864(n+2) cubed %K A189337 nonn %O A189337 1,1 %A A189337 _R. H. Hardin_ Apr 20 2011