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 A196203 #8 Mar 15 2023 11:30:07 %S A196203 1,5,7,35,135,899,10986,136967,3421139,111262773,5717068140, %T A196203 412501303097,44874896809668 %N A196203 Number of n X n 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 2,0,3,4,1 for x=0,1,2,3,4. %C A196203 Every 0 is next to 0 2's, every 1 is next to 1 0's, every 2 is next to 2 3's, every 3 is next to 3 4's, every 4 is next to 4 1's. %C A196203 Diagonal of A196210. %e A196203 Some solutions for n=4 %e A196203 ..0..0..1..1....1..0..0..0....1..1..0..0....0..0..0..1....0..1..1..0 %e A196203 ..1..1..1..0....1..0..0..0....0..1..1..1....0..0..0..1....0..1..4..1 %e A196203 ..1..4..1..0....1..0..0..0....1..1..1..1....0..0..0..1....1..1..1..1 %e A196203 ..0..1..1..0....1..0..0..0....1..0..0..0....0..0..0..1....1..0..0..0 %Y A196203 Cf. A196210. %K A196203 nonn %O A196203 1,2 %A A196203 _R. H. Hardin_, Sep 29 2011