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 A230190 #6 Jun 02 2025 08:43:10 %S A230190 0,8193,1223799,756450105,400233701367,218117038953009, %T A230190 117863748242661711,63824360296979648967,34546668873829672101987, %U A230190 18700870126913632045893531,10123031708751736005223316745 %N A230190 Number of 7Xn 0..2 arrays x(i,j) with each element horizontally or antidiagonally next to at least one element with value 2-x(i,j). %C A230190 Row 7 of A230184 %H A230190 R. H. Hardin, <a href="/A230190/b230190.txt">Table of n, a(n) for n = 1..23</a> %e A230190 Some solutions for n=3 %e A230190 ..0..2..0....0..2..0....0..2..0....0..2..0....0..2..0....0..2..0....0..2..0 %e A230190 ..0..1..2....0..2..0....0..2..0....0..1..0....0..2..0....0..0..1....0..0..2 %e A230190 ..1..0..1....0..0..2....1..1..1....1..2..2....0..0..1....2..1..1....0..2..0 %e A230190 ..2..1..0....1..1..0....0..2..2....0..0..2....2..1..1....1..0..2....0..0..1 %e A230190 ..1..2..0....0..2..1....0..0..2....1..1..2....1..0..0....2..2..0....2..1..1 %e A230190 ..0..0..2....0..1..0....2..1..0....2..0..2....2..2..0....2..0..2....0..2..1 %e A230190 ..2..0..2....0..2..0....1..2..0....1..1..1....1..1..1....2..2..0....1..1..1 %K A230190 nonn %O A230190 1,2 %A A230190 _R. H. Hardin_, Oct 11 2013