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 A197407 #7 Jun 02 2025 04:54:14 %S A197407 16,664,7232,199384,4499426,93153650,2065093081,45796265386, %T A197407 1003308210971,22026879283832,484764553481336,10667288376795442, %U A197407 234488008953014630,5155498381464737047,113400638560649259216 %N A197407 Number of nX6 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 A197407 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 A197407 Column 6 of A197409 %H A197407 R. H. Hardin, <a href="/A197407/b197407.txt">Table of n, a(n) for n = 1..164</a> %e A197407 Some solutions containing all values 0 to 4 for n=4 %e A197407 ..1..0..2..1..1..2....0..0..1..3..1..0....0..1..1..0..0..0....1..2..0..1..3..1 %e A197407 ..2..1..1..0..0..1....1..2..2..1..4..1....1..4..1..2..1..1....0..1..1..4..1..0 %e A197407 ..2..1..4..1..1..1....1..1..0..0..1..1....2..1..0..2..1..3....0..1..1..1..4..1 %e A197407 ..1..0..1..3..1..0....0..2..1..1..1..0....0..1..1..1..0..1....1..2..0..0..1..2 %K A197407 nonn %O A197407 1,1 %A A197407 _R. H. Hardin_ Oct 14 2011