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 A188845 #7 Jul 22 2025 11:24:42 %S A188845 7,49,219,958,3860,15358,59939,232747,899307,3468816,13362322, %T A188845 51445648,197998075,761910893,2931606169,11279434226,43396799102, %U A188845 166963886874,642368646269,2471408829291,9508325156265,36581628609584,140741386091368 %N A188845 Number of nX3 binary arrays without the pattern 0 0 1 vertically, antidiagonally or horizontally. %C A188845 Column 3 of A188851 %H A188845 R. H. Hardin, <a href="/A188845/b188845.txt">Table of n, a(n) for n = 1..200</a> %F A188845 Empirical: a(n) = 7*a(n-1) -10*a(n-2) -22*a(n-3) +57*a(n-4) +3*a(n-5) -77*a(n-6) +21*a(n-7) +42*a(n-8) -10*a(n-9) -13*a(n-10) +a(n-11) +2*a(n-12) %e A188845 Some solutions for 4X3 %e A188845 ..0..1..1....0..1..1....1..0..0....0..1..1....1..1..1....1..1..0....1..0..1 %e A188845 ..1..1..1....0..1..0....0..1..1....1..0..1....1..1..0....0..1..0....0..1..1 %e A188845 ..0..1..1....0..1..1....1..0..0....0..1..0....1..0..1....1..0..0....0..1..1 %e A188845 ..1..1..0....0..1..1....0..0..0....1..1..1....0..0..0....0..0..0....0..1..0 %K A188845 nonn %O A188845 1,1 %A A188845 _R. H. Hardin_ Apr 12 2011