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 A188749 #7 Dec 29 2023 10:47:33 %S A188749 13,169,1651,17286,184411,1944586,20544154,217243096,2296414963, %T A188749 24275369558,256625412014,2712870938389,28678635692942, %U A188749 303171638077403,3204930092906176,33880400190604953,358161194075528039 %N A188749 Number of 4 X n binary arrays without the pattern 1 1 1 diagonally, vertically or antidiagonally. %C A188749 Row 4 of A188747. %H A188749 R. H. Hardin, <a href="/A188749/b188749.txt">Table of n, a(n) for n = 1..200</a> %F A188749 Empirical: a(n) = 11*a(n-1) +2*a(n-2) -27*a(n-3) -420*a(n-4) -568*a(n-5) +3095*a(n-6) +2148*a(n-7) -2947*a(n-8) -4914*a(n-9) -3147*a(n-10) +1801*a(n-11) +4012*a(n-12) +2286*a(n-13) -228*a(n-14) -396*a(n-15) -656*a(n-16) -288*a(n-17) +192*a(n-18). %e A188749 Some solutions for 4 X 3 %e A188749 ..1..0..1....0..1..1....1..0..1....0..0..1....1..1..0....0..0..0....0..1..0 %e A188749 ..0..1..0....0..0..0....1..1..1....0..0..1....1..0..1....0..0..0....0..0..0 %e A188749 ..0..1..0....0..1..0....0..1..0....1..0..0....0..0..0....1..0..1....1..1..1 %e A188749 ..0..0..1....0..0..0....0..0..0....1..0..1....0..0..0....0..1..0....1..0..1 %Y A188749 Cf. A188747. %K A188749 nonn %O A188749 1,1 %A A188749 _R. H. Hardin_, Apr 09 2011