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 A189773 #8 Jul 22 2025 11:54:05 %S A189773 2,16,512,37976,7767740,3848548036,5404382625660,19742364192283882, %T A189773 203905576411742503606,5585800755853929115668714 %N A189773 Number of n X n binary arrays without the pattern 1 0 0 1 diagonally, vertically or horizontally. %C A189773 Diagonal of A189779 %e A189773 Some solutions for 5X5 %e A189773 ..0..0..0..0..0....0..0..0..0..0....0..0..0..0..0....0..0..0..0..0 %e A189773 ..0..0..1..0..0....0..0..0..0..1....0..0..1..0..0....0..0..0..0..0 %e A189773 ..1..1..0..1..0....0..1..0..1..0....0..0..1..1..1....0..1..0..1..0 %e A189773 ..1..0..1..0..1....1..0..1..0..1....0..1..0..0..0....1..1..1..0..0 %e A189773 ..1..1..0..1..1....1..0..1..0..0....1..1..1..1..0....1..0..0..0..1 %K A189773 nonn %O A189773 1,1 %A A189773 _R. H. Hardin_ Apr 27 2011