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 A197406 #7 Jun 02 2025 04:54:08 %S A197406 9,227,1626,25621,356211,4499426,60334353,801294395,10631272297, %T A197406 141478252511,1877225887699,24928405579380,331380977085358, %U A197406 4402455983432465,58475570189400714,776864156510384965 %N A197406 Number of nX5 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 3,0,1,1,1 for x=0,1,2,3,4. %C A197406 Every 0 is next to 0 3's, every 1 is next to 1 0's, every 2 is next to 2 1's, every 3 is next to 3 1's, every 4 is next to 4 1's %C A197406 Column 5 of A197409 %H A197406 R. H. Hardin, <a href="/A197406/b197406.txt">Table of n, a(n) for n = 1..210</a> %e A197406 Some solutions containing all values 0 to 4 for n=4 %e A197406 ..1..0..2..1..0....2..1..1..0..0....0..2..1..2..0....1..0..1..3..1 %e A197406 ..2..0..1..4..1....1..0..1..1..1....1..1..0..1..2....2..1..4..1..0 %e A197406 ..1..2..3..1..1....2..1..4..1..3....3..1..1..4..1....0..1..1..1..2 %e A197406 ..0..1..1..0..0....0..2..1..0..1....1..0..1..1..0....1..1..0..0..1 %K A197406 nonn %O A197406 1,1 %A A197406 _R. H. Hardin_ Oct 14 2011