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 A188993 #7 Jul 22 2025 11:31:12 %S A188993 8,64,295,1256,5304,21952,89744,364088,1469600,5913146,23742816, %T A188993 95207208,381443400,1527379724,6113711024,24465803130,97891852484, %U A188993 391642313112,1566765146976,6267573103552,25071633380208,100290042754410 %N A188993 Number of 3Xn binary arrays without the pattern 0 0 1 antidiagonally or horizontally. %C A188993 Row 3 of A188992 %H A188993 R. H. Hardin, <a href="/A188993/b188993.txt">Table of n, a(n) for n = 1..200</a> %F A188993 Empirical: a(n) = 8*a(n-1) -14*a(n-2) -29*a(n-3) +90*a(n-4) +12*a(n-5) -159*a(n-6) +36*a(n-7) +106*a(n-8) -35*a(n-9) -22*a(n-10) +8*a(n-11) for n>14 %e A188993 Some solutions for 3X3 %e A188993 ..0..1..0....1..0..0....1..0..0....0..1..1....1..1..1....1..0..0....1..0..0 %e A188993 ..1..0..1....1..0..0....0..1..0....0..1..1....1..0..0....1..0..1....0..0..0 %e A188993 ..0..1..0....0..0..0....1..1..0....0..1..1....1..1..0....0..1..1....0..1..1 %K A188993 nonn %O A188993 1,1 %A A188993 _R. H. Hardin_ Apr 15 2011