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 A197669 #7 Jun 02 2025 05:04:33 %S A197669 9,217,2765,44323,709083,11277331,178113620,2824369075,44803424135, %T A197669 710299706355,11259206241825,178502455899971,2830080961456550, %U A197669 44867619862024252,711321096455186766,11277240691421407939 %N A197669 Number of nX5 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,0,1,0,1 for x=0,1,2,3,4. %C A197669 Every 0 is next to 0 4's, every 1 is next to 1 0's, every 2 is next to 2 1's, every 3 is next to 3 0's, every 4 is next to 4 1's %C A197669 Column 5 of A197672 %H A197669 R. H. Hardin, <a href="/A197669/b197669.txt">Table of n, a(n) for n = 1..210</a> %e A197669 Some solutions containing all values 0 to 4 for n=4 %e A197669 ..0..1..2..0..0....0..0..0..1..2....0..0..2..1..0....0..2..1..1..1 %e A197669 ..0..1..1..0..3....0..3..1..4..1....3..0..1..4..1....1..1..0..0..0 %e A197669 ..1..4..1..2..0....3..0..1..1..0....0..0..1..1..2....1..4..1..3..0 %e A197669 ..2..1..0..1..1....0..0..2..1..0....1..2..1..0..0....0..1..1..0..0 %K A197669 nonn %O A197669 1,1 %A A197669 _R. H. Hardin_ Oct 17 2011